How do you explain a break up?

I found this website where an artist scribbles really cool messages on the back of business cards... Ever since I broke up with my ex in January, I'm faced with a ubiquitous question: WHY? Apparently, no one saw it coming but me.

So my question is: how do you explain a break-up?

If I had found this website earlier, I could have printed this card and passed it out in order to explain.

I know I complain about being in No Man Land but honestly, the greatest lesson I have learned this year is that when you're talking about marriage you are playing for keeps and in that context, no man is better than the wrong man.