Even Roger Federer once harboured self-doubts and the humble Swiss has expressed his relief at "living through a drastic generation change" to carve out a career of unrivalled longevity and excellence.
Federer will today face Frenchman Jo-Wilfried Tsonga in his 35th consecutive Grand Slam quarter-final, an amazing record that will surely stand the test of time.
But as he continues his quest for an unprecedented fifth Australian Open men's crown, Federer has revealed how he wasn't always so sure his graceful, old-school game would survive in the new age of power tennis and relentless baseliners.
"I came through in a generation where I was made to come to the net," said Federer.
"Because if I wasn't going to be at the net, the other guy was going to be at the net.
"When I started, I still played guys who volleyed extremely well back then, like Pat [Rafter] for instance or [Tim] Henman, Todd Martin.
"I played against many of those guys in the faster conditions so for me sometimes the only way to win points was to come to the net.
"For me, it felt very natural.
"Then obviously everything slowed down, the strings changed, the racquets changed a little bit and then I had to adapt as well to a new era, a new generation.
"Those guys started to bow out of the game and all the new players who came through were a lot of baseliners. There was a lot of topspin, there was a lot of physicality.
"So things changed and I'm happy that I was actually able to live through that drastic generation change as well.
"I was able to do both because I did grow up on outdoor clay and indoor supreme and that helped me to play as well in all conditions."
1 Victoria Azarenka (Belarus) v Svetlana Kuznetsova (Russia)
3 Serena Williams (US) v Sloane Stephens (US)
3 Andy Murray (Britain) v Jeremy Chardy (France)
2 Roger Federer (Switzerland) v 7-Jo-Wilfried Tsonga (France)