What if the things you are good at are not the things you love? What about the opposite? It is too complex to boil down to 'do what you love'.
"... [Cho Chikun] was asked by a Dutch reporter why he loved Go so much. Cho replied 'I hate Go'. He continued saying that it was too tiring and tense for him. This led to his habit of ruffling his hair or constantly moving about." -- http://en.wikipedia.org/wiki/Cho_Chikun
There's a glimpse of this in "The Master of Go". The author indicates there are different kinds of Go players—one kind, like Go Seigen, a light, bold, self-assured type that play every move as if they have perfect knowledge that it's the best one possible; the other being a dark type that always seem ill at ease, uncomfortable, questioning every move they make and pouring over their decisions for hours afterwards, like Minoru Kitani and current prodigy Cho Chikun. Strangely, the book brings up this dichotomy and never really classifies the main character, Honinbo Shusai, into one or the other category, mainly implying that he is somehow glacially slow, relentless and insatiable at the same time. Good book.
"Benoît Assou-Ekotto: 'I play for the money. Football's not my passion'"
http://www.guardian.co.uk/football/2010/may/01/benoit-assou-...
"The footballers that don't really like football"
http://www.guardian.co.uk/football/2007/apr/25/theknowledge....
Andre Agassi is one of the most interesting people, though.
Most people on earth are not defined by their jobs. They work because they have to. So he could be doing it for the money. Or the girls. Or the publicity. Or the lifestyle. Or the travel. He doesn't have to do it for the sport itself.
The "do something you love and you don't have to work a day in your life" is feel-good BS for relatively affluent or generally lucky in their life path people.
In any case, it only applies to "likable" jobs: a pilot, a manager, a doctor, an artist, a chef, a journalist, a teacher, a programmer etc. E.g jobs that a lot of people CAN find interesting and fulfilling.
But most of the world goes round by the non-likable jobs. Maybe some people like those jobs too --but they are bizarro outliers. The vast majority of people doing them do not like them.
E.g I don't think many people "love" flipping burgers at a McDonalds, washing dishes, or working 16 hour shifts in a mine, or cleaning the streets from garbage. But they do because they have to --until something better comes along. And a lot of them have kids and such dependent on them, they cannot leave it all behind and go chase some Hollywood dream or whatever.