alt Hacker News> Deciding what to work on might be the most important question in life.
The flip side of this, is if you have the ability, you can just pick the hardest problem in your field, go solve it... rinse and repeat.
Everyone can find out what the hardest problems in their field are, it's not a secret, just a question of if you have the ability/gumption/willingness to go spend years of your life attacking a problem like that
Finding the hardest solvable problems in your field is far harder.
Prove P = NP
(or not).
Is definitely one of the hardest problems in computer science, but you could waste your entire life on that problem and make no progress. Innumerable great contributions to the field have nothing to do with that problem. Booting Linux in JavaScript wasn't even on most people's maps.