Sri Lanka centurion Kumar Sangakkara admitted the tourists had "fallen short" on their tour of England after a 1-0 defeat in the three-match series.
Sangakkara, standing in for injured captain Tillakaratne Dilshan at the Rose Bowl, struck a superb 119 to help them avoid defeat in the third Test.
"We're a side in transition, but in a way we've fallen short," he said.
"Everyone can look at themselves and think they could have done things better over the past few weeks."
Sangakkara, who resigned as Sri Lanka captain in all forms of the game in April, stepped in for Dilshan for the third and final Test with his team already 1-0 down in the series.
England were confident of bowling the visitors out on a grey morning on the final day with Sri Lanka resuming their second innings on 112-3, still 81 behind England's first innings tally.
But Sangakkara's first Test century on English soil, combined with dogged resistance from nightwatchman Rangana Herath (36) and a wonderful unbeaten 87 from Thilan Samaraweera, ensured Sri Lanka had done enough to secure a draw by the time rain fell during the tea break.
"We knew what we had to do," added the 33-year-old who was playing in his ninth Test in England. "We had two sessions to save the game and we were happy to do the job.
"There were various situations that could have played out today, but we batted with our heads held high and played our shots and it was much more satisfying doing it this way.
"My technique has always been pretty good but there are a few adjustments you need to make for playing in England. It's a bit late, but I'm happy to have finally scored a century here.
"We will learn our lessons from the tour, there are many things to ponder, but it's been a great experience and a lot of the players have been superb in the last few weeks."
Sri Lanka's interim coach Stuart Law could not hide his delight at seeing his team battle to avoid defeat against England's impressive bowling line-up.
"I'm thrilled for the boys against what is an awesome attack," said Law. "They just had to find a way to survive and that's what they did, so hats off to Kumar and Thilan.
"The team have found it difficult with the extreme bounce Chris Tremlett was getting, but they scored runs quickly and played some great shots, it was a really pleased effort today.
"Kumar was up for a fight. He had read some things and seen some things on TV and he wanted to show that Sri Lanka weren't going to lay down and die.
"It's been a learning curve for me as well as the players. I'm learning the role, not just to do with cricket but off the field as well, and I hope things are progressing in a manner both parties are happy with."
Sri Lanka's players were subsequently fined 20% of their match fees by the International Cricket Council for maintaining a slow over-rate, after match referee Alan Hurst ruled that they were two overs short of their target by the end of the game.
Stand-in skipper Sangakkara was fined 40% of his fee, while Sri Lanka accepted the penalty without contest.