Mixing up dates and times, not just forgetting them

TL;DR short version:

I'm starting to miss out on events and meetings because I don't realise that 9:30 minus 1.5 hours is NOT 9:30, it is 8:00. Also, Friday plus two days does not equal Saturday, it's Sunday. And if yesterday were Saturday, then yesterday cannot be Friday.

I feel so sure of a schedule in my head that I feel no need to double check the time. And I don't realise that there's a mistake in my logic. Why?

Detailed version:

Why am I stupid? My brain isn't making the most obvious connections, so I'm starting to miss meetings, events, etc. FYI I am 27 years old, male, grew up and live in Toronto, hold a permanent job as an engineer-in-training, so in theory I should be good with numbers and logic. English is my first language.


I signed up for a hiking meetup event. I knew the start time at the location would be 9h30 and the required driving time from my city to the park is 1.5 hours. I also signed up to join a carpool there that would have left my city, but I thought I read that that carpool would be departing at 9h30. For some bizarre reason, I hadn't realised that the carpool time I thought I read didn't make any sense, since we would need 1.5 hours to drive there. Anyways, I felt so confident that I had all the details correct in my head, I didn't bother to double check the carpool time or the meetup time before setting my alarm for 8h00. So my plan for the next morning was:


8h00: wake up

9h00: leave the house to go to carpool pickup location

9h30: join the carpool to ride to the park. Ride would be 1.5 hours long

9h30: arrive at park after a 1.5-hour ride and start the hike.


Yes, I had this "schedule" memorized in my head. I felt confident about this schedule, and didn't think anything was wrong, even though I now realize that it's physically impossible to leave my city and arrive at the park both at 9h30. And I was fully aware that the ride would have been 1.5 hours long.


As I was leaving the house, I decided to double check the precise pickup location within the pickup place. That's when I finally read the correct pickup time was 8h00, which was the time I set my alarm to wake up! It turns out that I read the carpool pickup time incorrectly, but I never would have suspected my mistake had I not double-checked on my way out. I ended up missing the hike.

If I had this schedule memorised confidently, why didn't my brain alert me that something was wrong with the schedule I had in my head? Had my brain alerted me that my logic was faulty, I would have urged myself to double check the pickup time the night before, but I didn't, because I felt so confident everything made sense!


This isn't the first time I screwed up. I remember doing this as a kid, when my mom reminded at 8h15 to wake up for school. At that moment, I thought to myself "Oh, it's only 8h15, and I normally wake up at 8h15. Therefore, I have another hour to sleep before I have to wake up at 8h15!".


Then there was this time when I promised to volunteer on Saturday, the 14th of April. I set myself a reminder in my outlook calendar so that I don't forget: Satuday, 14th of April. No problem! I double check my calendar on Friday the 13th of April, the day before, to remind myself that I have this event on Saturday the 14th of April to help out with. I also sign up for this evening-dinner meetup event on Saturday the 14th of April, which wouldn't have conflicted with my daytime volunteer work. So on the night of Friday the 13th of April, my plan for that weekend was:



Day 1: Saturday the 14th of April:

relax during the day

get ready for the evening dinner on Saturday the 14th of April

After dinner, go home, sleep for the night



Day 2: Saturday the 14th of April:

wakeup at 8h00 and get ready to volunteer for the day.


On the real Sunday the 15th of April, thinking that it's still Saturday the 14th of April (even though the day before was Saturday the 14th of April, and I'm fully aware of that), I go to the venue excited to help out, but no one's there. Then a staff walks by and says that I missed the event the day before. I look at my phone to check the date: today was Sunday the 15th of April! And for some reason, I knew it was Sunday and thought that I would helping out on an event that would happen on Saturday!

It's not like I can't remember the dates and times, it's that I feel so confident that I have the dates and times correct (and that my schedule logic is correct) that I don't realise that my scheduling logic and my dates/times are actually incorrect. Why isn't my brain making these simple connections and alerting me that something in my logic is wrong? 9h30 minus 1.5 hours does not equal 9h30. Friday plus two days equals Sunday, not Saturday. Do other people commonly make these mistakes, such that they're confident they didn't make a mistake?


I'm quite sure my reputation as one of the meetup organisers with this group is ruined.

Do you sleep 7+ hours a night? Do you exercise (cardio)? Various things worth checking for in a blood test - just search "brain fog related blood tests" in google and bring all you think you should get checked to your primary care doc.

If you have good sleep cycle and exercise enough, next thing you should try is fixing diet (if of course it isn't already good). Try gluten free. Try lowering sugar intake. Try paleo. These are all things I've tried and lack of sleep/exercise have a huge effect on me. I still have major cognitive processing issues but they make me worse. Diet not so much for me but everyone is different.

Of course, explain your symptoms to the doctor. He'll likely want to check your blood for the more serious possibilities like Lyme disease that need to be caught early.

mbwndhoufk wrote:TL;DR short version:

I'm starting to miss out on events and meetings because I don't realise that 9:30 minus 1.5 hours is NOT 9:30, it is 8:00. Also, Friday plus two days does not equal Saturday, it's Sunday. And if yesterday were Saturday, then yesterday cannot be Friday.

I feel so sure of a schedule in my head that I feel no need to double check the time. And I don't realise that there's a mistake in my logic. Why?

Detailed version:

Why am I stupid? My brain isn't making the most obvious connections, so I'm starting to miss meetings, events, etc. FYI I am 27 years old, male, grew up and live in Toronto, hold a permanent job as an engineer-in-training, so in theory I should be good with numbers and logic. English is my first language.


I signed up for a hiking meetup event. I knew the start time at the location would be 9h30 and the required driving time from my city to the park is 1.5 hours. I also signed up to join a carpool there that would have left my city, but I thought I read that that carpool would be departing at 9h30. For some bizarre reason, I hadn't realised that the carpool time I thought I read didn't make any sense, since we would need 1.5 hours to drive there. Anyways, I felt so confident that I had all the details correct in my head, I didn't bother to double check the carpool time or the meetup time before setting my alarm for 8h00. So my plan for the next morning was:


8h00: wake up

9h00: leave the house to go to carpool pickup location

9h30: join the carpool to ride to the park. Ride would be 1.5 hours long

9h30: arrive at park after a 1.5-hour ride and start the hike.


Yes, I had this "schedule" memorized in my head. I felt confident about this schedule, and didn't think anything was wrong, even though I now realize that it's physically impossible to leave my city and arrive at the park both at 9h30. And I was fully aware that the ride would have been 1.5 hours long.


As I was leaving the house, I decided to double check the precise pickup location within the pickup place. That's when I finally read the correct pickup time was 8h00, which was the time I set my alarm to wake up! It turns out that I read the carpool pickup time incorrectly, but I never would have suspected my mistake had I not double-checked on my way out. I ended up missing the hike.

If I had this schedule memorised confidently, why didn't my brain alert me that something was wrong with the schedule I had in my head? Had my brain alerted me that my logic was faulty, I would have urged myself to double check the pickup time the night before, but I didn't, because I felt so confident everything made sense!


This isn't the first time I screwed up. I remember doing this as a kid, when my mom reminded at 8h15 to wake up for school. At that moment, I thought to myself "Oh, it's only 8h15, and I normally wake up at 8h15. Therefore, I have another hour to sleep before I have to wake up at 8h15!".


Then there was this time when I promised to volunteer on Saturday, the 14th of April. I set myself a reminder in my outlook calendar so that I don't forget: Satuday, 14th of April. No problem! I double check my calendar on Friday the 13th of April, the day before, to remind myself that I have this event on Saturday the 14th of April to help out with. I also sign up for this evening-dinner meetup event on Saturday the 14th of April, which wouldn't have conflicted with my daytime volunteer work. So on the night of Friday the 13th of April, my plan for that weekend was:



Day 1: Saturday the 14th of April:

relax during the day

get ready for the evening dinner on Saturday the 14th of April

After dinner, go home, sleep for the night



Day 2: Saturday the 14th of April:

wakeup at 8h00 and get ready to volunteer for the day.


On the real Sunday the 15th of April, thinking that it's still Saturday the 14th of April (even though the day before was Saturday the 14th of April, and I'm fully aware of that), I go to the venue excited to help out, but no one's there. Then a staff walks by and says that I missed the event the day before. I look at my phone to check the date: today was Sunday the 15th of April! And for some reason, I knew it was Sunday and thought that I would helping out on an event that would happen on Saturday!

It's not like I can't remember the dates and times, it's that I feel so confident that I have the dates and times correct (and that my schedule logic is correct) that I don't realise that my scheduling logic and my dates/times are actually incorrect. Why isn't my brain making these simple connections and alerting me that something in my logic is wrong? 9h30 minus 1.5 hours does not equal 9h30. Friday plus two days equals Sunday, not Saturday. Do other people commonly make these mistakes, such that they're confident they didn't make a mistake?


I'm quite sure my reputation as one of the meetup organisers with this group is ruined.

You sound like a very busy guy and I would think it is probably mental fatigue. I've went through stretches like this when I've been extremely busy, overwhelmed at times and I start to forget things like that. Little details that aren't super critical to your overall mission in life. Gone through the same anxiety about it as well and self-critique.....then something changes, internally and/or externally and everything is "right" again/firing on all cylinders. I would guess that you are just "operating at capacity" or close to it constantly and some of the info that you try to commit to memory gets "misfiled" in your brain. It also sounds like you try and hold yourself to very high standards and are very self-critical when you see yourself as falling short.

The hiking meetup was not a huge deal, probably more embarrassing than anything. Part of you saw remembering the time as not "life or death" so it was not ingrained in your memory. I would find it hard to believe that if the appointment were for an important interview or a meeting with you boss that you would get it mixed up.

I think you shouldn't be so hard on yourself and maybe you need to do the opposite by giving yourself a little break, maybe take a weekender excursion. It always helps me to clear my head and refresh my mental state.

I try to do a lot. Sometimes I attribute schedule mixups and misses to simply being overwhelmed. There are times when my mind 'whites out', races and goes blank. I try to remember the last thing I was thinking about in order to get back on track.
I keep a paper list in my pocket now with appointments, phone numbers, grocery list and things to do, etc. I transfer the remaining things to a new list when the old list gets worn out.
I spoke to my doctor about this and they have just started me on Sertraline (Zoloft) about 2 weeks ago. My physical exam numbers look good, which is reassuring. I get stressed and shaken when I make mistakes.
I am hoping for an improvement in mental performance.
Best of luck to you.