I used to think the best time to be a father was when the kids were old enough to communicate well with me. But I was mistaken, in several ways.
I found that at each stage of their life, there is a different way of communicating. And it's a learning process for me: how to communicate well at their level, and teach them at the same time. And each level builds upon the previous one.
And in particular, because I'm always learning, there's a richness to be gained all the way through.