I'm sure it's covered in his book too but I haven't gotten it yet. Heard this last August:
http://www.npr.org/templates/story/story.php?storyId=12389154some snips (starts with interviewer Steve Inskeep, alternating paragraps are Biden)
......
You did end up, at a relatively young age – mid-40's – running for president the first time…
Yes.
…and being forced to withdraw from that race because of news stories about quoting someone without attribution in a speech, because of quoting without proper footnoting in a paper when you were in law school. I wonder if, regardless of whether you consider yourself innocent or guilty as charged, whether you think it's appropriate that people look into the biographical incidents and search out the character of presidential candidates, as opposed to their positions.
Totally appropriate.
It was appropriate for people to look into that.
It was appropriate to look into it. But I wish they had looked into it. They didn't look into it. And had they looked into it, they may have reached a – and some did ultimately – a more balanced conclusion. But the bottom line was, I made a mistake. I did not, in the debate in Iowa, attribute what I said. And it was born out of my arrogance. I didn't prepare for the debate. It was stupid. I didn't deserve to president. I didn't deserve to be president just based on the Richter scale of 'Was I tough enough and did I understand the process?'
Are you saying the system worked…?
The system worked.
…in shoving you out before you even got to the election year?
In a strange way, it did work.
Has it been hard to wait 20 years for another shot at the White House?
No. As a matter of fact, I didn't make a political speech outside of my state for 20 years. And I just focused almost exclusively on my initiatives for national crime legislation, foreign policy issues…
You weren't waiting for another chance?
No. And what I finally decided this time – and I had no intention of running, I worked very hard for John Kerry…
In 2004.
In 2004. And after John lost, which was a real kick in the head, I realized that if I really meant and cared about as deeply as I do the issues I care about, I wasn't going to be able to affect them very much in the Senate.
...
Last question, Senator. You said that 20 years ago, you didn't deserve to be president. Do you now?
Yes. I'm the single most qualified person in either party on the problems that most urgently face America. When this president is constitutionally required to hand off power to the next president, he will leave the next president with virtually no margin for error. This is no place for on-the-job learning.