When you're rich, you can obsess over this sort of nonsense. The rest of us have lives to lead, pg.
Choose happiness? Did George Washington choose happiness? Did Oppenheimer or von Neumann choose happiness? Or Stanley Kubrick? Or Faulkner? How about Steve Jobs or Ken Thompson? Or Bill Gates or Linus Torvalds? Or Elon Musk?
Why not choose obsession? Why not choose dedication, and commitment?
I say choose fulfillment.
Saying "choose happiness" is like saying, "I've built this great foundation for a magnificent building, but I don't feel like building it. I'll just sort of hang out and let people admire this great foundation." Of course you need to be happy to achieve anything. Unhappy people do not get very far in life, same way buildings with no foundation do not stand for very long.