I'm not one for New Year's resolutions, but this is absolutely one I can stand behind. I'm actually proud to say that I came to this conclusion myself about 2 years ago and have been doing a bang-up job at it ever since. It really does allow you to live in the moment more and also introduces you to the concept of Enjoy & Let Go. As a perfectionist at heart, this was a big step for me.
Skip the sciency stuff in the article and just read the main points. Here's a preview if you're feeling untrusting and don't want to click the link without a general idea...
"People can become very focused on an ideal. Even if they know it's unlikely, they get so focused on the perfect scenario that they block everything else. Or they anticipate that they'll kick themselves later if they take second-best option and then see that the best one is still available. But they don't realize that regret can go the other way. They'll end up with something worse and regret not taking the best one."
Link from Barbara Winter