Thank you! I agree with you and I actually wrote three articles about, which might help answer your question.
https://steemit.com/life/@mrs.steemit/life-lesson-you-have-to-be-childlike-in-the-pursuit-of-your-life-but-you-cannot-be-childish
This one is about what I generally believe: You should be stubborn on the goal, not on the approach!! Meaning, if it is in the area of possible (if you are able to imagine it clearly) then there is a way. And then the other article:
https://steemit.com/motivation/@mrs.steemit/monday-musk-motivation-responsibility-future-and-perception-of-fear
(Elon Musk about fear of failure) and then..
https://steemit.com/life/@mrs.steemit/psycho-cybernetics-part-2
an excerpt from the book "Psycho-Cybernetics" (worth buying) that explains how we humans function and in regards to achieving a particular goal. The R.O.I is there, the math has been done many times. It simply comes down to understanding your own abilities, the area of possible and then steering yourself to that return-on-investment you seek. This is such a huge topics, but hopefully this is somewhat of help :)