You have regrets, and thinking about them consumes much of your time. If only you had done that differently, had worked harder, had thought that through more carefully, had taken a bigger risk: much of life is a series of “if onlys”. You stand back and evaluate where you are right now and you consider what you wanted and what you actually have are very different from one another. Perhaps you could have held on to those friends more tightly if you had worked harder on those aspects of your personality you don’t particularly like. Perhaps you would be fulfilling your dreams if you had spent less time investing in people and helping them achieve theirs. Perhaps you would love yourself more if you did not feel you had disappointed so many others.
The worst part is when you realize that the one you have most greatly disappointed is yourself.