I wonder the same for athletes. Was recently reading Nadal's biography and parts of book describe his routine in childhood and teenage. And my first thought on reading that was "what if he hadn't made it to the top?" because he essentially had no semblance of a regular childhood/teenage. Being out on the field at 5am day after day, year after year seems only worth it in hindsight if you make it to the top.
I guess, in the end, Gita captured this as well: the only way to be able to put extraordinary effort is to not care about the outcome.