AD&D was my 2nd rpg.
The first (technically) was Twilight 2000, simply because I had no money in my early teens and found a copy for ten bucks at a clearance sale, and my only geek friend was just as much of a military nerd as I was. We spent dozens and dozens of hours with that book, making ludicrously overpowered and over-equipped characters … and then doing nothing with them, because neither of us had any real idea what an rpg was or how to play one, and the T2000 book just kinda assumed you already knew so it had absolutely no explanations or play examples for newbies.