You like to make commitments on your own terms, but you're no commitment-phobe. If you up and leave a stable relationship or take your time in committing, it probably isn't because you think the grass might be greener somewhere (or with someone) else. It's that you want to make absolutely sure that when you commit to one person for the long term, you're doing it from the heart, and not based on anyone's expectations but your own.
You've always been attracted to unique people, after all; people who excite you and surprise you on a daily basis are the ones who really rev your engine and warm your heart. And sometimes, this type of person can be hard to pin down! But you'd gladly trade in a bit of stability for even more fun and excitement. You know that sooner or later, you'll find that perfect blend of the two, and that's when you'll stake your claim. If you've already found that balance, good for you! If not, have fun, and rest assured that you'll find it someday. You may go through several longer-term relationships before finding one that you really want to stick with through thick and thin, and if so, that's okay -- it's part of your process.