My friend Stephan and I came up with a theory long ago that 90% of mens actions are based on the fact that somewhere in the back of their mind they think that it will help them either get or keep girls.
Shaving- Men dont really like to shave as often as they do but men like women.
Working out- Working out is alot of work but guys know it will help them get girls. Sure, people like to feel in shape but that because they mainly like girls to tell them they look good.
Cars- Men like cars. Its a fact. They also think about hey if I had this fast car when I go on a date this girl will be so impressed.