Hi... I need some advice

So... I was cleaning out my desk or whatever and i found a letter i got from one of my old best friends from when i lived elsewhere. It was like... around 9 years old. I can't even remember if i ever did write him back. We've been out of contact for like... again... 9 years. I kind of want to write him now, like 9 years later, but do you think it'll just be wierd or something cool like a pen pal kinda thing. If you got a letter from your best friend in pre-school 10 years after last seeing them mostlikely forgetting all together who they are then suddenly this letter pops up... what would you think? Ahh... please help me i don't know wether to write or leave it alone and just forget it. Thanks.