It is quite a mystery to wonder how domestication happened at all, though seeing how modern wolves can be made (relatively) tame and biddable if you get them as pups, maybe it just took one person to have the idea. I imagine you would have been quite the badass in early human society with a tamed wolf at your side.
So maybe rather than some semi-spooky pan-human thousand year plus directed domestication effort it grew organically with people inter-breeding their captive tamed wolves?