Happily ever after?

I really thought we would spend the rest of our lives together. This sucks, but I have to move on. The worse part is that the break up was for no reason. There was no cheating or arguments. It started with her saying "I need space" so I gave it to her. A few months later she's interested in somebody else lol. Ain't that about a bitch?  To make a long story short, she wanted to see other people and use the "I need space" crap to do it. I Just don't understand how someone can throw what we had away as if it was nothing.