One Tree Hill, Season 4

Lucas:
[voiceover] Regret comes in all shapes and sizes. Some are small , like when we do a bad thing, for a good reason. Some are bigger, like when we let down a friend. Some of us escape the pains of regret by making the right choice. Some of us have little time for regret, because we're looking forward to the future. Sometimes we have to fight to come to terms with the past. And sometimes we bury our regret, by promising to change our ways. But our biggest regrets are not for the things we did... but the things we didn't do. The things we didn't say that could save someone we care about. Especially when we can see the dark storm that's headed their way.