He got bored of pursuing you, and eventually clued in that no matter how long he tried, nothing would've changed, so he friend-zoned you. He still wants to hang around with you, and possibly move things towards a friends with benefits situation, but as to a relationship, the clock has stopped ticking.
I was involved in a similar situation.
When he stopped pursuing you, it appears you started to get interested in him as more than friends. Next time you might just want to avoid the lengthy "friends only" phase, and give it a shot. You have to either decide whether it's more important to be platonic friends with someone, or take a chance that the friendship might come to an end if things don't work out.
You can either keep the friendship as is, or go to him and tell him exactly what you want. If the fires of interest he felt cannot be re-ignited, move on and find someone else for a relationship.
i could not have said it better myself!