Earlier quoted context omitted.
It's not just you. My fear is opposite to the one the author describes: That by using these services, all these messages that I treat as ephemeral are actually being recorded forever, and 20+ years from now something I said offhand to a friend or a stranger will be used to embarrass or discredit me.
Unless you are a very prominent politician or on track to become one what do you care? I don't know... I more or less stand by what I have to say or I can honestly say that when I said it I was "young and stupid".
"I was young and stupid" only works if the content in question is trivial or unimportant. If you happen to be on the opposite side of a political debate long since settled, you may end up getting yourself pwned pretty hard, even if you're not a politician.