Turns out this week is D&D’s 40th birthday! I’m slightly older than it is, and have been playing for somewhere around 30 of those years.
My first D&D game was in a car on the way to a Boy Scout camp. It was diceless and mostly rule-less. I joined in progress; one guy had Blackrazor, one had Whelm, and one had a crossbow. Encounters usually ended with us all trying to kill each other as well. Good times. (I find it interesting that nowadays people contend you can’t play D&D diceless, or can’t play it PvP… Kids nowadays.)
I was always more of a SF guy so I played Star Frontiers, but got frustrated with buying Dragon Magazines for the Ares section and not being able to use or understand the rest (What’s a “hit die?”) so got the original Red Box, and then it was off to the races!
So thanks to D&D for many years of fun. I still play it (even though it’s called Pathfinder now)!
Geek Related 
My brother got the red box back in the late 1970’s for Christmas. We didn’t understand it and never looked in the box again. In summer of 1980, some kids were playing on the bus and I slowly got into it. Got some AD&D books of my own, and have been playing ever since.
We were totally confused by the AD&D “to hit” table at first. I recall my friend not wanting to raise a level, because he thought it would make it harder for him to hit things!