Ambition
Ambition has a strange relationship with time. We give up parts of the present for a better future, but once we reach that future there is usually an incrementally better one ahead of it.
A large part of this is hedonic adaptation. When we achieve something difficult, we are often surrounded by others who have achieved the same thing. Our instinct is then to become more successful than this new group.
When everyone around you is similarly smart and ambitious, being more successful usually requires greater sacrifice, mostly in the form of more time and mental space spent working, and less attention given to health, family, relationships, and the rest of life.
There is also an asymmetry to memory. Once something has been achieved, the work that went into it fades surprisingly quickly. The result becomes normal, even if it once felt distant or unlikely.
The most ambitious and fulfilled people seem to be ambitious about the journey itself. They care deeply about what they are doing, not just what succeeding at it will buy them. Ambition around money or status feels much more closely tied to insecurity and comparison.
I do not think the answer is to want less. It is to spend your ambition on something you would still care about even without the status attached to succeeding at it.