Dating question, how do I get my head on straight?

Sorry for the vague question title.

For most of the last ten years, I’ve been in relationships with one silly guy or another. I don’t really try or seek them out. Life just sends someone along, and they’re cute/amiable/interesting so we strike up a friendship, and before I know it we’ve been dating for a few months or a few years. I go into most of them feeling like, “hey, this person is all right! I’d be happy to hang out with them some more.”

Then eventually, cute, friendly, and interesting isn’t enough. All of these relationships have ended with me feeling disappointed in the guy- and in hindsight, I’ll see the the seeds of that disappointment from the first time I met him. They’ve all been fun and positive experiences during, but once they’re over it’s the same sort of feeling as when you read a trashy beach novel. Like, “what have I learned from this?” or “that’s it?”

Am I a pretentious jerk, or have I been dating shallow people, or what? This question comes from a very recent breakup, and it’s the first time I’ve finally started to notice this pattern. The best thing I could do right now is spend a good chunk of time being single and sorting things out. ...but.

I’m interested in someone, and I think it’s the real deal this time. He’s the dorkiest, most hapless guy ever, but his character, it’s so great. He’s intellectually curious, introspective, kind, and sincere; he’s always challenging himself, and always learning something new, and we share the same values. I just admire the shit out of this dude because he’s such a great person. I’ve known him for about two years.

He’s also fifteen years older, and he’s someone I know professionally. Obviously we’re in for a lot of road bumps if I pursue him. He’s gone on some unsuccessful online dates, but as far as I know, he’s never dated… anyone, really. (He’s introverted and socially awkward and has a lot of uncool, indoorsy interests, but… I have all of those things, too! It’s common ground, and I actually think his awkwardness is cute and endearing.)

For the first time, my gut instinct says this could be the guy. My brain thinks so, too. I’m inclined to spend a few months being single, sorting out my feelings, etc, before I decide whether to make a move. Beyond that, any advice?