I remember when it went from D&D to AD&D,,,,,,ehhh youngin'? 
Actually...AD&D and D&D co-existed for a while..Even into second edition AD&D. D&D was actually fairly stable a system,
with not much in the way of changes before WOTC basicly did away with the A in AD&D...Really, Dungeons and Dragons 4th Edition
is more of a D&D 2nd Edition that just separated out the Race/Class divide as opposed to being just the Races and Classes were one
and the same. At least, that is the impression I got looking between the original white page edition and the ORIGINAL red box..