He did work hard till 03, then he stopped it, that's why today 2 other guys are tied with him on 20.
Whatever actions we do the ripple effect/the butterfly effect we see a lot later..... not immediately
After that he won his first Wimbledon, then fired his coach, went without coach for 1-2 years, he so far ahead of his closest competitor Roddick that he was feeling Kingly and not in need of a coach, then next gen Nadal arrived and still Fed brushed Nadal off as if he is not that big a deal despite some defeats here and there, instead of curing the backhand problem he was being Kingly, then he was seeded 2 for the first time in slams in 5 years at AO09 and before that he exclaims that it feels weird to be announced world number 2, the sound of it is wrong? Wtf... .
... That is the epitome of entitlement. Then he still did not learn, Novak was coming up and Nadal already was somewhat ahead by 2010 but he still did not change his racquet...... tried to outhit them and thought he could overpower them in 10-13 with his puny racquet, some 4 good years lost. 14 onwards he started his renaissance with Edberg, a decade too late.
As our friend and fan of Martinka
@Jason Swerve would say, not maximizing your efforts in your early years and later also in your peak is what cost you to struggle in old age vs youngsters who will not let you win as it is their time. This is the result, the slams race should have been 26-17-17 types today, however it is 20-20-20 and Novak has stripped him of some crucial records.