The most famous example, the one single case that epitomizes thousands of others who fell short, is JOSH WAITZKIN.
A chess prodigy. Dominated the US scholastic chess scene from age 9. Drew a game with Kasparov at age 11. Had Pandolfini as a coach. Too many titles to list here. Made chess his life.........
Yet he never rose above International Master. There are thousands of other kids who all have the makings of the next Fischer, but hit that IM ceiling.
Try telling Waitzkin he just didn't work hard enough...he was a bit too lazy at chess. If I were Waitzkin and someone told me that, I guarantee I'd bust him in the chops and then stomp on his face. Yep, that's what I'd do.
You youngsters have a lot to learn about life. There are some things, no matter how hard one tries, that cannot be accomplished.
God, I only wish becoming successful at something was as simple as putting in hard work.
+1
@elubas : about time vs. work - I don't consider playing games without analysis as work. Many players (especially youngsters) develop by playing games and picking patterns along the way.
Some pick those patterns much more efficiently than others, and I also count it as a 'natural aptitude' for chess, wherever it comes from.