If he's slow at crawling, he's most likely fast at something else
So true, I reckon.

I think babies have "pockets" of learning. Some have big gross motor skill pockets, others fine motor, and others verbal........

(Whilst Olivia never moved much, she could manipulate sorting toys brilliantly, so the point where some of the other Mums in my mothers group thought their babies were "slow" at things like that. And NOW they are all at the same level in most skills.........)