Spock met Jim when he was 7 and Jim was 6. It has since been generally agreed that this was a mistake (or: the one where they grow up together and things are simultaneously better and worse for it).

Winona is called to fix the cock-up of the Yorktown's engines. She uses one of the science-bitches to help her do it. & This is not exactly what Jim thought the 'exploring strange new worlds and exotic civilizations' was about. Also, Vulcans are kind of crazy. Jim and Spock go through a alien ritual, which, yes, changes everything -- he's hoping for the better. Spock just wants to get through this with his sanity, if not his dignity, mostly intact.

Sometimes the other Vulcans wonder how Spock managed to obtain such an exotic bondmate, and sometimes Spock wonders himself.