I do believe that there is an element of luck in life.
However I also believe that those who are prepared for it are more likely to notice and fully use things that come their way.
Furthermore it is also true that people like to protect their egos . One of many ways is to avoid comparison with people they think more successful. This can be done by putting them on a pedestal, cutting them down to size, or ascribing their successes to luck.
For all of these reasons, even though I believe that some things just happen, I agree with Asimov that people who seem to have "all of the luck" generally don't. And people often ascribe things to luck that aren't really luck.
But a final note. One point made in [link|http://www.jimcollins.com/ViewPub.asp?id=186|this article] by Jim Collins is that the very best CEOs always look to outside forces to ascribe success to. That means people around them, circumstances, and if all else fails, luck. So even the very best, it seems, may confuse their own accomplishments with sheer luck. :-)
Cheers,
Ben