There’s a sense of renewal to the first week of a Grand Slam. Each day, various potential futures briefly announce themselves, before packing up their racquets and heading to the next far-flung stop on the circuit, not to be seen again for months. That’s been especially true in Melbourne this time around. Walking to the far corners of the grounds in search of fresh faces and new talent, you can see the sport beginning to repeat its own history. Nineteen-year-old Grigor Dimitrov is the Federer-esque high-flyer, Bernard Tomic is the crafty, junky Andy Murray wannabe, Bojana Jovanovksi is the next Serb star, Ricardas Berankis has his nose to the same grindstone as Nikolay Davydenko.

Whether of not any of these futures comes to pass is still very much up in the air, and that's the reason we keep watching from one “generation” of players to the next. We want, in the accelerated way of tennis, to find out who does what with their lives. In this game, we get to find out much more quickly than we do anywhere else. At 29, Roger Federer is already a lion in winter. Venus Williams is on her last legs at 30. Caroline Wozniacki better hurry up and do something already before she turns 21. Rafael Nadal is entering the prime of life at 24. Notice that Nadal measured his age yesterday as “24 and a half." Everything is compressed in a tennis career, every month a precious one not to be wasted. As soon as you start, the end is in sight.

Time is a jet plane, someone said, it moves too fast. It takes the ridiculous acceleration of pro tennis to remind us of that fact and make it visible. The stages of the cycle play out through the first week of a major, as the future inevitably runs up against the present. Jovanovski gave second-seeded veteran Vera Zvonareva a run yesterday, before experience and polish won out. Stan Wawrinka showed Dimitrov what professional-level consistency looks like. Berankis, on the other hand, caught another vet, David Nalbandian, on a weary-old-man day when he couldn’t recover. On Saturday, the generational drama will play out in a high-profile way inside Laver Arena, when Nadal takes on Tomic.

I can remember when, six years ago, in this same round and on this same middle Saturday, Nadal was cast in the Tomic role. He was also 18, and he was playing local hero and Top 5 resident Lleyton Hewitt. You could see Nadal had the tenacity and the consistency, but the confidence to break open points wasn’t there yet. (As he was for Federer, Hewitt was a sort of litmus test for Nadal; Rafa played him close a few times before breaking through and leaving him in the dust.) Nadal lost in three close, arduous sets.

Rafa, now in a very different role, was in an expansive mood yesterday. The idea of playing the prodigy of the moment brought out his nostalgic side. In the process, he summed up the bittersweet element of getting older in tennis. The things you desired—wins, Slams, rankings, recognition—bring as much anxiety as they do happiness.

He was asked, “When you were a teenager playing against the best in the world on your way up, how did you did you approach the games? What was your attitude?”

“Is much easier when you’re a teenager, I think," Nadal said, warming to the opportunity to wax philosophical. "When you have 17 or 18, everything is easier. You play with no pressure. You can win, you can lose, everything is fine. That’s a different mentality. You can play more aggressive. For everybody is the same history I think, no?"

Nadal smiled and fiddled with the top of the water bottle in his hand. He kept going. “When you arrive, you hit all the balls like crazy and without think, without pressure. When you are there [raising his hand to indicate a high level] you start to think a little bit more about you have to play this shot, you have to play another shot, I can’t lose this match, I have to win this match for sure.

"That’s little bit more problems. When you are coming up, you [make the] quarterfinals, perfect; semifinals, fantastic; you play final, very good; and if you win, is unbelievable. You lose in quarterfinals, you say, ‘Well, is good. Is not my tournament,’ but you are going back very happy at home.

"So that is different view and different perspective of the game. So the pressure is higher when you are in the top. Seems like it could be different, but believe me, that’s what happen.”

Nadal kept smiling; his teeth virtually glowed out from his tan face. He took a sip of water. He’s on top of the mountain at the moment, and it’s hard to imagine him anywhere else in the immediate future. But he knows, perhaps better than the rest of us, that the moment will pass. As a tennis player, he’s learned that fact early.

“The day of today, I am lucky. I have 24 and a half. I won what I win, what I won in the past, and that’s more than what I ever dreamed.”

Nadal shrugged. He’s fulfilled his dreams, but he also says that 10 minutes before his next match, he’ll be nervous again. Life goes on, nerves go on. For tennis fans and writers, there’s always a new generation to enjoy coming down the pike, forming before our eyes. The price of throwing yourself into the center of the arena is that you only have one shot; life is fantastic there, but it's over fast. Nadal will be anxious when he faces the new generation. Knowing him, it will drive him to keep the future at bay a little bit longer. He knows time is passing too fast to waste a day.