Your story is very thorough and all the info is there. Let me just tick down the facts I gathered, OK?
- Yes, you two liked each other
- No, you two had no real foundation
- He smartly made sure you made your career choice based on you
- You chose smartly
- You regret not being able to develop a relationship with him, but it's regret, nothing more...you didn't actually "have him" to lose
- You cite confusion, but it's really just sadness and regret over what never really came to fruition between you two
- Further attempts on your part to turn your romantic reminiscence into something more were smartly avoided by him, proving there really is nothing there
- You're sad about it all and playing the "what if" game in your head in your free time
OK, that's it. You know there's nothing really here to chase, you'll get over the sad stuff when you successfully redirect those energies into a relationship where you ARE, not where you used to be. You physically moved, time to let your mind make the move, too.
Good luck dear, lots can happen when you stop looking over your shoulder.