The pursuit of happiness is inextricably wrapped up in the inevitable that sometimes you will fail in your pursuit. The pursuit of happiness often comes with great sadness and obstacles you encounter trying to attain your dream. But as Americans, we are at least given the hope that we can pursue something resembling happiness. It is so engrained in the fabric of our country that we mostly take for granted our freedom to make these choices. 

If one does X, then one receives Y.

Couldn't be simpler. If one mows the neighbor's lawn, the neighbor will reward you with some money. If you clean your room, you receive an extra Twinkie. Punch the bigger kid, get clobbered. Do the crime, do the time.  Quid Pro Quo. If X, then Y. Call it The Transactional Life. 

The difficulty in growing older or up or however you choose to look at the passage of time is that you start to see that this contract with the world, this Transactional Life, is not fair. Most of the time, the value you place on X is not in equal proportion to the perceived value of Y.