A family friend was my 7th grade school bus driver. One day he found a coverless copy of the Expert Set rulebook. Reading through it, he immediately saw that it was something I'd be interested in, and passed it along to me.
It took me a week or so to fill in the gaps enough -- remember, all I had was the Expert rulebook -- to start building my own dungeons, but it was awesome. Even if those early dungeons had lots of stuff like vampires and giant scorpions and no, you know, dragons. Or, for that matter, orcs.
I got the Basic Set and the full Expert Set that year at Christmas. The first adventure I ran for my friends was Palace of the Silver Princess. I clearly remember thinking how utterly genius boxed text was.