The thin Line between...

I wonder what borders define compulsive lying. Where does the line pass? I mean what if you lie a lot, feel like its an urge, like you must do it, and its usually the default option. But you can decide to tell the truth, its just harder and it takes more dedication and will.
Sometimes the lie can be about stupid and small things and sometimes it can be about bigger things.... Like lying about the fact I left 80 grams of gunpowder in my balcony to dry and it caught on fire and the entire balcony was on fire. I think I actually broke the law when I took things out of there before the investigator came. Lied to my parents and they lied to the investigator despite the fact they are so against lying and $#%^...