A lot of scientists, interestingly, are willing to admit a luck factor, especially when it comes to doing something Nobel-Prize-level world-changing. Some really did know exactly what they were doing, and it worked. But a lot of scientists frankly admit that the big career-making thing they did wasn't even something they thought was important at the time--- and sometimes nobody else thought it was important either, and it languished in a journal for 10 years before someone else noticed it had big implications. Of course, that's not purely luck, because they'd never have had that opportunity to get their work belatedly discovered if they hadn't done good work on interesting problems, and published it. But there does seem to be some element of luck in the work turning out to be huge. There are plenty of people in exactly the same position who do good work on interesting problems, write a good journal article, and it doesn't turn out 10 years later to have unexpected but important implications, winning them the Nobel Prize. Just sort of how it happens; you can't always predict what is going to turn out to be important.

I could be wrong, but my impression is that wealthy businessmen are somewhat less willing to admit the role of luck than famous scientists are. Due to real differences in the role of luck in the two areas? Due to political considerations (the implications of admitting that wealth disparities aren't all due to merit are more political than the implications of admitting that scientific fame isn't purely due to merit)? Due to the self-deprecating scientists being humbler personalities? Dunno. And I could be wrong on the aggregate difference; I haven't done a survey or anything.

Luck is important, no doubt. But a)first you must follow your heart; b)you must do great work; and c)then you probably deserve some luck, too, and/or create your own luck.