He Should Know Better At His Age

What a time to walk by and catch the middle of a conversation:

A woman is insistent that someone should have known better than to do whatever it is that he did.

The listener asks, "Well, how old is he now?"

She says "He just turned one year old.

"Well, he should know better at that age."

What in the world would you ever think that a one year old should know to do or not do?