This is a really interesting question, naynay. You're right, the answer seems so simple. I only share this in a very mixed way -- a few things I'll get that way about (usually involving doing something special and hoping the receipient is happy and bummed when they don't give a crap), but mostly I'm in the "don't get your hopes up then you can only be pleasantly surprised if something actually goes well" camp. And so am kind of trying to do the opposite -- to have a little more hope in how things might go. So there are a few things I'm holding in this state. One is huge. It's hard, but I'm trying.

But all these things are connected somehow. I'm curious to hear if some folks that have dealt with this in therapy jump in. The last part you wrote seems to indicate perfectionistic tendencies. That sure seems like it'd be involved (I've got them too, but I catch myself sometimes -- say (out loud, lol) "Getting obsessive. Stop! Good enough!"
It actually works sometimes.