One big difference between men and women is that if a woman says ”smell this”, it usually smells nice.

How true. One day, when our son was about 3, he came in from playing outside, put his hand up, and told me to "smell this." Having formerly been a 3-year-old boy, I told him I didn't have time to, but he should ask his Mom. Naturally, she did and quickly regretted it.

I didn't even try to warn her. I wonder if that might be one of the reasons she always introduces me as "my first husband..."?

Another big difference: there's no talking in the men's room.
My wife also learned the reason for this from our son. We were teaching him to use the toilet. He was standing there quietly; I was quietly watching from one side, and my wife was standing directly behind him. He started to go, and my wife naturally starting clapping and telling him what a big boy he was. Smiling, he turned around to receive his praise - and that's when my wife discovered why guys don't talk to the other guys in the men's room.