From David Hume’s An Enquiry Concerning Human Understanding:
Where am I, or what? From what causes do I derive my existence, and to what condition shall I return? … I am confounded with all these questions, and begin to fancy myself in the most deplorable condition imaginable, environed with the deepest darkness, and utterly deprived of the use of every member and faculty.
Most fortunately it happens, that since Reason is incapable of dispelling these clouds, Nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation, and lively impression of my senses, which obliterate all these chimeras. I dine, I play a game of backgammon, I converse, and am merry with my friends. And when, after three or four hours' amusement, I would return to these speculations, they appear so cold, and strained, and ridiculous, that I cannot find in my heart to enter into them any farther.
According to the hedonic treadmill theory, we are all predisposed to return to a relatively stable level of happiness, regardless of how many good or bad things might happen to us.
I think this is both saddening and reassuring.
On the one hand, we’re never likely to find durable satisfaction. Every new experience we have, every milestone reached, every possession acquired, will eventually lose its luster. The new car smell fades, we grow accustomed to the people around us.
But, just like Hume, we might also find ourselves lost in existential dread, and the vastness of the universe. And then, the mundane aspects of life – a good meal, a game with friends, engaging conversation – pull us back to reality.
It’s not such a bad thing to have the reassurance of a happiness set point.