Men tend to be like snowflakes, each snow flake is distinctly different and beautiful but they are all made of ice water and they all want to land on top of you and then evaporate

But I am generalizing and I am talking about men who were born with penises and testicles, whom had the full testosterone levels present during the typical times, etc.
My experience and the experience of other women (typically) is that men don't get better after you have sex with or marry them, they tend to relax and to not try as hard. The trying harder to be a better man tends to be part of the courtship, not part of the relationship.