Have you ever noticed that in the aftermath of a breakup we often focus on the good things about our ex or the relationship, and tend to gloss over the things that weren't working?
You keep thinking about how fresh her hair smelled, and forget about her habit of interrupting you in the middle of a sentence. You focus on how nice he was to your dog, and draw a blank on the fact that he forgot your birthday, your anniversary, and Valentine's day.
There's no absolute answer on why our memory suddenly becomes so selective right after a breakup, but one thought is that when a relationship ends, one of our biggest fears is that the investment of our time, energy, and hearts wasn't worth it since the end result wasn't what we had expected. One way of protecting ourselves from this fear is to emphasize the good parts of the relationship and ignore the less-good parts. This way we don't feel like we were wrong or stupid to be in it in the first place.
But if we're willing to accept that the relationship can have had value and good things about it, AND that it ultimately didn't work for us and wasn't meant to continue, we don't need to rewrite history and torture ourselves with the thought that we've lost this (supposedly) beautiful, perfect thing in our lives. We get to see the relationship for what it really was, appreciate what it gave us and taught us, and move forward in our lives to greater happiness.
~ Notes from BreakUp Land, by Sasha Carr, Ph.D.