How do you know when you've found 'the one'?

There's a guy that I have been friends with for 2 years that I always thought his girlfriend of 5 years was lucky to have him. Anyway to cut a long story short he broke it off with her last March. SO anyway we had been nothing but friends, and had no body contact at all (not even a hug or handshake ) in the whole time he was dating his ex. So I told him I was emigrating to Paris for a year he was shocked and in my last few weeks we spoke every night on the phone. 3 weeks before I left...he kissed me. It was so bizarre but also felt quite natural afterwards. I'm finding it hard to forget him and its been 3 months since I left. We get on really well, we have the same values etc etc. I've never dated anyone I've been friends with first so not sure what to think. I'm hoping to spend some time with him at xmas when I go home for the holidays but he's adamant that he needs to remain single for a year to recover from his ex. Should I wait for him - or find some y french replacement?