Yes! Absolutely!
I know exactly what you are talking about.

From the moment he was born, he was alert, and all the other babies had these glazed looks. It was very noticeable (and not just to us, people would comment on it).

At preschool, I notice it too, but it's more subtle now. It just seems like DS is more alive, more alert, more intense. It's like an adult plopped inside a 3yo body. I don't know how else to describe it.

That said, at classes, DS is usually not the one listening or following directions. I think the pacing is too slow for his mind. He often tries to speed it up by following his own agenda, or he amuses himself in his head. I think the constant waiting is just too much for him. That little brain never stops.

An example. He is the kid who isn't keeping up in swim class. He is too busy trying to figure out swimming on his own (and half drowning). I really think it's a pacing problem. Giving him bits and pieces at a time is exhausting, when he just wants a major brain dump all at once. lol.

Lastly, he rarely napped his first year of life. It was exhausting. I think he didn't want to miss anything, you know?