Lance Armstrong is not an idiot ... he knows he screwed up in Aspen last year -- and now, he's finally talking about it.
Armstrong appeared on "TMZ Hollywood Sports" this week to talk about why he's participating in Bo Jackson's "Bo Bikes Bama" charity ride on May 2nd.
During the conversation, Lance talked about how much Bo's support has meant to him during some of his tougher times. He also talked about spin class and beer pong.
That's when he brought up the incident in Aspen -- where he pled guilty to careless driving after crashing into two parked cars back in December.
It's the first time he's mentioned the incident ... and he took total responsibility.
Check out the clip.