Are we just larger versions of two year olds?

I am noticing my little nephew – being at a family wedding – he is very interesting to watch.

He can’t speak, but his identity is fully developed – he knows what he wants and he wants it now.

But what’s interesting to note – obviously – is that he only imagines he knows what he wants, for what he actually wants, is nonsensical; whether it’s his pastime of throwing things into the toilet bowl, basically, whatever catches his fancy at the moment, becomes a life and death issue for him!
Are we just larger versions of two year olds?!