The cricket season started for me yesterday (one run, a dropped catch and no bowling, if you're interested) Mostly because I decided not to fence a competition in order to be available for the cricket, it raised for me the difference between the things we really love doing, and the things that we happen to be good at.
A lot of the time, these two things are quite easy to confuse. After all, we tend to enjoy doing well at things. More to the point, when people really enjoy something, whether it's writing, a particular job, or flunging past sabreurs at high speed, they tend to put in so much time and effort naturally that they get rather good at it. Take Steve Vai, for example, whose approach to the guitar as a youth seems to have consisted of playing all day, every day, because he didn't want to do anything else.
But sometimes, with the things we're merely good at, it's the feeling of success that we're enjoying, not the activity in question. Not that there's anything wrong with that, but it's important to realise that the two things are seperate. As an example, take the Durham and England fast bowler Steve Harmison. He was, briefly, the number one bowler in world cricket. Even so, it's been widely publicised that, given the talent to do so, he'd much rather be playing football for his beloved Newcastle United.
This is the point where the divergence becomes important: when what you really love doing is not the thing that you happen to be really good at. Should you be doing the thing that you enjoy that you aren't much good at, or the thing that you're good at that you don't enjoy so much? To a great extent, it becomes a question of degree. It's never likely to be as clearly defined as "I'm a world-beater in this but I hate it", though "I really love this but I'm utterly hopeless" shows up rather more often. Instead, it's likely to be a question of being above/below average at two things, one of which you really love, but the other of which you find quite fun too, after a fashion.
I suppose it's the sort of thing that you can see in the scenario of a well paid job that you sort of enjoy set against the thing you've always dreamed of doing, but which might go horribly wrong. What's the answer? Typically enough, I don't know. My own experiences with this interest v ability thing see me occasionally going for the thing I really love (though I'm thinking of changing my mind on that on the cricket v fencing front), occasionally going for the thing I'm good at (which is how I ended up doing this PhD), and occasionally trying to do everything all at once, with fairly chaotic results.