I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times.

We could not trace this famous line to a specific primary source in Bruce Lee's own hand, but the attribution is strong and consistent. When asked, the Bruce Lee Foundation affirmed the quote as authentic, crediting the family's own archive, and a variant of it ("I am not afraid of a person who knows 10,000 kicks, but I am afraid of a person who knows one kick but practices it 10,000 times") appears in the Lee proverb compilation Wisdom for the Way. The sentiment is unmistakably Lee's: in a 1967 letter to his student and appointed instructor Taky Kimura, he preached exactly this "economy of form" \u2014 that a student masters more by drilling a few essentials to perfection than by chasing an ever-growing menu of flashy techniques. What we cannot confirm is a dated, verbatim original for the polished English wording most often circulated, which reads more like a refined restatement than a documented Lee sentence. On the evidence, the idea is authentically his and the attribution is sound, even if the exact phrasing has no single traceable source.