Nature built in the ONE thing that everyone needs to do and that is to produce and raise offspring. It's hard as hell and will occupy the greater part of your life for 20 years or so doing utterly mundane stuff, as well as force you to make a certain amount of money, but there is nothing better. When old folks are comparing images on their phones, nothing trumps a grandbaby. Nothing. "You climbed Mt. Everest with a Sherpa on your back? Take a look at little Emily in her cute outfit!"