Bob, I'm surprised that your Mum and/or Dad didn't have this conversation with you as a healthy adolescent lad...
You see, when a Mommy and Daddy windmill (with superior genes), that love each other very much, decide that they should reproduce... Nine months later a turbine(s) is born!
I can explain it to you but I can't understand it for you.
"Any man who thinks he can be happy and prosperous by letting the Government take care of him; better take a closer look at the American Indian." - Henry Ford
Corruptissima re publica plurimae leges; When the Republic is at its most corrupt the laws are most numerous. - Publius Cornelius Tacitus