Sorry, but I can't agree with that attitude, at least not from a motivational perspective. With that view, why bother coming down from the trees in the first place?
The mindset you describe is good to make yourself happy, and useful in that context, but useless to make your life better (by any metric).
I believe one can be both happy and have the ambition to continually make the world a better place through one's achievements.
Happiness, fulfillment, and a 'better life' are all different concepts [though not mutually exclusive]. It's also all completely subjective, so whatever works for you is correct.
I have no idea why we came down from the trees. It's quite nice up there.
The mindset you describe is good to make yourself happy, and useful in that context, but useless to make your life better (by any metric).
I believe one can be both happy and have the ambition to continually make the world a better place through one's achievements.