I had a very sudden and intense relationship last year. We had been friends since school and it was very very right at the time.
I ended up breaking it off as he wouldn't commit in even the smallest way. He wouldn't set a date to next see each other, but would call me at 1am on a friday expecting to be invited over etc.
I know if he had some maturity we would have been great together, and I think he has now realised the same. But it's too late for me.