Nostalgia making me crazy

I am not sure if I am posting this in the right forum but here goes.. I discovered a diary recently from my high school days . Reading through it I became overcome with nostalgia. I had described my first crush in detail as teenagers do, and of course, with social media these days I looked him up online. I found that he lives near me now and the urge to contact him is driving me nuts. I would love to see him again.

This was not even a boyfriend, we did get together once but it was more just a crush and the diary has caused me to relive it, now I feel like it just happened yesterday!

What do I do? Leave it alone and hope it passes or drop him a line? Chances are he will either think I am nuts or not recognise me at all. It's been 20 years!
Any advice appreciated