Luck helped. Work helped. Honest people give each its fair share of the credit.

Both explanations are usually true at once, and people reach for whichever one suits them. Crediting only the work makes you hard on everybody who did not get there, because it implies they simply did not try. Crediting only the luck lets you off the effort that really was yours to make. The accurate version sits in the middle and is less satisfying than either.

Take something that went well and name one piece of luck in it out loud: the timing, the teacher, the family you landed in. Then name what you did that was not luck at all. Doing both keeps you honest and keeps you working.