Luck is an interesting concept. Many of the successful people I know consider themselves lucky. Not just from a “I’m lucky to have been successful” standpoint, but from a “chance events usually seem to benefit me” standpoint. Part of this is undoubtedly self-fulfilling: no matter what happens, winners see opportunities and have the fortitude to exploit those opportunities for their benefit. (And, on the other side, losers see the impediments and have cultivated the attitude of accepting things they could change if they had a different outlook.)
It should be obvious then that winners don’t really count on luck at all. Whether everything goes perfectly, or everything blows up in their face, they will find the opportunity in it, find out how to use it, and eventually be “lucky”.
This concept is totally different from truly believing you’re lucky, in the sense that chance events are going to benefit you or that one day, the gods will smile upon you. That’s dangerous. This is the attitude that leads people to believe that the life they’ve always wanted is just one lottery ticket away.
It’s much better to believe that you’re unlucky. That random, chance events will never benefit you, and to know, in your gut, that the only way you’re going to succeed is to work hard, to slog through the disappointments until you finally get it right.