This question on Quora currently has 123 answers: I have everything I thought I wanted and I'm still not happy. Why?

One answer that's getting buzz:
No offense, but I completely disagree with the top answer, by William Franceschine. It's a very common view of things from the Western perspective, but there is a different way of viewing life and happiness.

You've achieved your goals and still aren't happy, so set new goals and work for them? That's the gist of the top answer, but it doesn't make sense, does it? Isn't it clear that those goals as well won't satisfy?

Zen Buddhism teaches that the solution, what leads to lasting happiness, is to stop chasing these goals. To practice true appreciation of the present time and place, without dwelling on the future or the past, what you don't have and want, or what you have but don't want.

You can learn about Zen and its practice without necessarily becoming "religious" in the Western sense about it. Much of it can be thought of as a philosophical practice. I recommend looking into it.

Eventually you can learn to be happy with the way things are. I think this sounds funny or even stupid to goal-seeking, materialistic Westerners (not all Westerners), but many people have followed this practice; especially people in your situation, after having attained so much and realizing they still aren't happy—even the Buddha himself, who was born into a wealthy family and had everything that was supposed to make him happy, yet wasn't.