Exactly, redpepper!! Thanks for relating your experience.
I have also done the casual thing and it was painful because I really loved certain people, but hid it. And I also have done the break-up after break-up, finding something "wrong" with the person.
It's such a relief to realize one's true nature, eh?
Even my recent experiences with polyamory were mostly defined as one, primary, committed relationship and others on the side. This caused similar problems. I get sucked into expecting way too much from one person.
I really want to explore having relationships without the "anchor" of a primary. If something more serious were to develop with someone, I'm open to it. But, right now, I need to not be tied down to being the main squeeze of one person.