I started with the Moldvay/Cook basic and expert set JUST before the Mentzer basic came out. I learned enough to start a small (me and two others) group in sixth grade in 1983. Maybe the Mentzer set was already out but hadn't made it to rural Kentucky yet. I got the 1st
DMG and S4 for Christmas that year. At that time, I was the first person to ever hear of D&D at my school (or, for that matter, in my county). Hell, we thought "Advanced" must be what came after "Expert". The Mentzer sets were very helpfull in getting new players as I could lend someone the Basic player's book and they could learn a lot without intense tutoring. Thanks to them, by 8th grade our group was sanctioned by the school and had grown 10-12 members (as well as becoming one of the "cooler" clubs at school). So, while not "starting" with Mentzer, most of the guys I've gamed with since '83 did. In fact, one of my first two players is starting a BECMI/Rules Cyclopedia game for his kids and me while I run 3.5 for them