The been article linked to upthread starts off "Lance Armstrong, 41" makes you remember just how young he must have been when it all kicked off, which probably explains a lot. So I went to have a look at his Wikipedia entry and in Motorola: 1992–96 and read "1992 ..He .. collected the Thrift Drug Triple Crown of Cycling" and "In 1994, he again won the Thrift Drug Classic". He's always been good at that drug stuff, then.
More seriously, what must it feel like, at 21, to feel you might have the world in your grasp? So do many others, yes, not looking to excuse, just wondering.