I stumbled across an interesting article about how your digital life will follow you whether you want it to or not. (Read: I Called Off My Wedding. The Internet Will Never Forget).
My rule has always been, be mindful of what you post; assume that everyone will read it and that it will exist forever. The Internet will hold on to things that you may want to forget, or let go of, or wish never happened, making the process of moving on or moving past something much harder that it was at any other point in human existence.
In the “good ol’ days” you would tell your friends and family, “I don’t want to speak of this any more,” and that would (hopefully) be the end of it. People may gossip behind your back (how humans love to gossip), but it was, for the most part, over. The memories lived in your head, and you were able to remove (most of) the reminders in the physical world around you. Not so any more.
The Internet is the friend who hears everything you say to it, shares it with everyone it knows (and it knows billions of people), and never forgets any of it. It is an amazing friend, great for so many things, useful in so many ways, but with a potential dark side.