Why is it so hard to believe that life doesn't exist in space.

I'll assume you meant "life does exist..."

If that's the case, I don't recall a recent post here that suggests otherwise. But I think some of us have a degree of difficulty with the notion that aliens are crossing lightyears of space to rip up some cattle and trample patterns in wheat fields. "I Want to Beleive" can be misleading mindset.

I personally agree with you that it seems likely (to my layman's mind) that life exists elsewhere, though there have been some prominent thinkers (and I'm not talking theologians) who have suggested that life might in fact be very rare. Apparently the chain of events that leads to life (as we currently understand it) is extremely long and easily broken, and there are huge areas of space that can't be called Habitable Zones (closer in toward the galactic core, for example, the radiation levels are apparently quite lethal.) So while calculating the odds of extraterrestrial life *may* still be a numbers game, the numbers themselves may not be easily discerned. I'm just conveying what I've read, perhaps the more qualified in here will correct me if I'm wrong.

I guarantee it's full of life...
You could be right, you could be wrong. We don't know.