A cynic is not merely one who reads bitter lessons from the past, he is one who is prematurely disappointed in the future. — Sidney J. Harris. Topics referred to by the same term Cynicism
Regret for the things we did can be tempered by time; it is regret for the things we did not do that is inconsolable.
Nothing can be so amusingly arrogant as a young man who has just discovered an old idea and thinks it is his own.