The fact that babies learn to make sense of the world is amazing just in itself.
It's truly amazing to see how much babies can learn!
Granted, gifted kids may be more likely to be interested in books and legos, but that doesn't mean that the interest is necessarily abnormal.
I guess I wasn't surprised that he likes books/legos. I am just surprised that he can sit still for 15+ minutes for anything, or that he keeps trying to put lego blocks together even though his fine motor skill isn't mature enough to do that yet.