Every Profession has it's own pros and cons. But you can survive in some professions easily. It is not the case with Trainers or Body Building.
There is very little scope for Luck. You work hard, Keep diet consistent then only the muscle will grow not like we keep A,B,C,D on the OMR sheet and voila we get a good grade or the Interviewer did not know anything and we get an easy job with fat pay.