No one is ever satisfied, largely true, but there is dissatisfaction that leads to action (I see myself out of shape --> I exercise), and dissatisfaction that leads to sadness, depression, feelings of unworthiness (I see myself out of shape --> I cry hugging a macaroni and cheese). If a romantic interest rejects you, how do you react? Do you cry and cry and feel the biggest loser on earth or you look around and tell yourself: there are other 10,000 potential romantic interests in this place?

Dedicating oneself to something you want to accomplish, be better at, have fun with is always the answer. The answer, on the contrary, very rarely (never?) comes from deep introspection that inevitably ends with meaning-of-life question.