The 26-year-old Dubliner is due to have surgery on the dislocated shoulder he sustained in the first Test next week, and watched on helplessly on Saturday as the battered and bruised Lions lost the second Test, and ultimately the series, with a 48-18 defeat in Wellington.
The Leinster and Ireland centre said today: "It (the tour) is a lost opportunity, because whenever you get picked for the Lions, you are expected to go down and win Test series, whether it is against New Zealand, Australia or South Africa.
"Tours are always judged on their success, and this one will go down as a disappointment, but I have felt that on my previous (Lions) experience four years ago, the enjoyment factor of this tour has been far more significant than then.
"But it is all about winning in the end, and you just have to accept it.
"My over-riding disappointment is not getting the opportunity to play more than 45 seconds in the Test series, which is what you go on Lions tours for, to play the Test matches, and not to get the opportunity is a disappointment, whether you win or lose."
In addition, O'Driscoll spoke of his admiration for Graham Henry's All Blacks side, who on Saturday in Auckland, will gun for a first Test series whitewash of the Lions by any team for 22 years.
"When you look at the clinical way in which the All Blacks played, I don't think any side in the world playing well would have been able to live with them," added O'Driscoll.
"Comparing it to (the Lions tour) four years ago, they are certainly a more difficult side to beat than Australia were."