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).

What it says on the tin. (Including Follow-ups to: Maybe one of these days you can let the light in, and One Of Those Things, and Mrs and Mr Pond..)

"Commander Spock, we have located your son," the Vulcan lady on the screen says, which would be great, except Jim can tell by the look on Spock's face that he's never heard of this kid before in his life. "If it is expedient, the child will be sent to join you on the Enterprise within the week."

Just your every day modern street gang of ragamuffins.

"'Spock,' Jim breathes out, completely overwhelmed by the gesture—not quite believing that Spock knows him so well, that's he's already started researching, that he trusts Jim with a member of his own endangered species." When Jim gets it in his head to adopt an eight year old Vulcan, Spock presents a logical solution to the issue of Jim's humanity: marriage to a Vulcan citizen.