You are confusing luck with expectation. Luck is the deviation from expectation. I've seen terrible poker players win a big tournament, or crush cash games for months on end, and quit their jobs because they mistakenly believe they are skilled at poker. Their positive deviation above their actual expectation (their "luck") soon evaporates, and they moan constantly because their results begin to actually match their expectation, or even worse, they get "unlucky" and their losses are greater even worse than their expectation.