My 2 cent since I read alot into these topics:
There are made 'prodigies' and then there are real prodigies, and then there are exceptional prodigies.
Made prodigies are those where 'prodigy-ness' have been thrust on them, forced. Once they have complete control over their life (read-reach 18 years old) then interesting stuff happens. Some really do enjoy it and keep it that way, but in less rigorous way, in order to catch what they been missed in their life. Some will rebel.
Real prodigies are just kids who really loves something and totally into it. Just like some are introvert and some are extrovert and its hard to change someone from one to another, some kids are just into stuff - whatever that is. I don't know if you consider Slash (guitarist) as prodigy (music) although he might not known or popular when he was a kid, but for me it doesn't change the fact, but the moment he saw people playing guitar when he was a kid, he built one from his broom and simple string and practiced till his grandmother bought him a real one. And he still playing to this day. The same can be said about Neil Tyson. Saw the stars when he was a kid, and he is who he is now.
However, some kids get better attention than the others, and better resources too, and considered prodigy. Some, are lost. If you are a Aghanistan or Iraqi kids today, how can you access to robotic stuff when you are too busy not getting bombed?
So, some of the kids do get resources. Like chess class, music class, access to professionals, healthy diet, etc. But these kids, when they grow up, will deal with people who try to gain the same access and attention like they too, so finally they will even out.
And then there are exceptional prodigies. These are when nature helps them out, and nurture could push things better. I will always use the story of the memory prodigy for this: the guy who can memorize everything people say without knowing it, and thought that everybody can also do the same (http://en.wikipedia.org/wiki/Solomon_Shereshevsky). And the likes with photographic memory. Unlike savants, they have the best of both world.
Some people brains do wired differently (like seing numbers and alphabets in colours). And these are exceptional prodigies who last to their adulthood, unless, they decided to slow down, or burn out due to over exposure or just plan to have a change of life style.
http://en.wikipedia.org/wiki/William_James_Sidis
In short, there are many type of prodigies and you just cannot group them together. Its hard to know which is which, but in the end you will notice.
http://mentalfloss.com/article/27906/9-child-prodigies-who-actually-ended-doing-something
I think the list should be longer, but the names eluded me. So to say that a prodigy end up just like normal people when they are old, is wrong. Some are exceptional when they are kids, and stay exceptional for a long, long time.
edit:
there are many example, but I think Bobbdy Fisher can be used here.
- He was into it himself, not forced.
- He was lucky to be given resources
-
"In May 1949, the six-year-old Bobby, and his sister Joan, learned how to play chess using the instructions from a chess set bought at a candy store below their Brooklyn apartment.[22][23] When Joan grew disinterested in chess, and Regina didn't have time to play, it left Fischer to play many of his first games against himself.[24] When the family vacationed at Patchogue, Long Island that summer, Bobby found a book of old chess games, and studied it intensely.[25]On November 14, 1950, his mother sent a postcard to the Brooklyn Eagle newspaper, seeking to place an ad, inquiring whether other children of Bobby's age might be interested in playing chess with him. The paper rejected her ad because no one could figure out how to classify it, but forwarded her inquiry to Hermann Helms, the "Dean of American Chess", who told her that Master Max Pavey would be giving a simultaneous exhibition on January 17, 1951.[26][27]Fischer played in the exhibition, losing in 15 minutes. One of the spectators was Carmine Nigro, president of the Brooklyn Chess Club, who introduced Fischer to the club and began teaching him.[28][29][30] Fischer attended the club regularly, intensified his interest, and gained playing strength rapidly. In the summer of 1955, the then 12-year-old Fischer joined the Manhattan Chess Club, the strongest in the country.[31][32] Fischer's relationship with Nigro lasted five years, from 1951 to 1956,[33][34] when Nigro moved away to Florida.[34]"
- And he might get tired (being a human) and might need rest.
"After the World Championship in 1972, Fischer virtually retired from chess: he did not play a competitive game in public for nearly 20 years"
- But that will not change who he is.
"After twenty years, Fischer emerged from isolation to play Spassky (then tied for 96th–102nd on the FIDE rating list) to a "Revenge Match of the 20th century" in 1992."
"The purse for Fischer's rematch with Spassky was US$5 million, with $3.35 million of that to go to the winner"
"Fischer won the match, 10 wins to 5 losses, with 15 draws"
Now that is real, exceptional, prodigy,
And oh, old habit die hard.
"On December 10, 2006, Fischer telephoned an Icelandic television station and pointed out a winning combination, missed by the players and commentators, in a chess game televised live in Iceland."