There will always be that someone whom you adored much but was never yours. There will always be that question of "what if?" that you'll never get to know the answer. There will always that something that will never go away even though time has gotten over it.
Regret comes in many forms; some are still being lived at the moment, while some are buried inside the heart. Some are being compensated through friendship, while some are just nightmares we don't want to talk about. But there will always be a choice between just thinking what could have been and knowing what could have been. Sometimes all it takes is a little courage to do the risk. But sometimes we chose to stay as what we are, not because we're cowards, but because we value the person that we are right now more that the person that could have been.