Psychology always fascinates me. Let's observe young children. Boys love toy cars, robots, building blocks and experiment things, while girls love toy make-ups, stuff toys and barbie dolls.
Men invent and repair things and women keep them and make the place tidy. Men don't plan but can see the dangers ahead - and always proud of that skills. Woman always love to put on her "princess shoes" and think of the "happy ever after". (Speaking of shoes - I never knew a woman who has only one pair of shoes that lasts for a year and matches all sorts of clothes.)
I agree that men always think of "sex" (though not the explicit act always). Men tend to notice the opposite sex - first the woman's face, then the shape of her body. That proves that men are very visual and women want to be noticed and always yearning for commitment. Men also notice other men who look superior to them and release the "defensive and territorial hormone". They will try to control that feeling and observe, but that "ready-to-fight" feeling is always intense. Women notice V-shape men and trendy women too but they are more concerned about what's happening around, latest fashion and gossip.
If men think most of the time about sex, who invented sex toys?