Sure, you don’t expect Rafa Nadal to lose in the fourth round only a few weeks after winning his 14th slam. Not to Nick Kyrgios, ranked 144th in the world. Not to a 19-year-old with a racing stripe shaved into his head. Even Kyrgios’s mom said she thought he wouldn’t win. And yet … the real shock is that it wasn’t a shock. Before the match, a friend and I were talking about whether Nadal would match up better against Kei Nishikori or Milos Raonic in the quarterfinals when we stopped ourselves. If he makes it that far, we said. If.

There were the obvious reasons to worry. Rafa isn’t the player on grass that he was when he made five Wimbledon finals in six years (and skipped the tournament the year he didn’t). His troubles are obvious and well catalogued. He seems to have difficulty finding his footing on the fresh, slick surface, especially early on in the tournament. His high-bouncing topspin forehand is partly neutralized as it skids on the turf. His bad knees make it harder for him to get low. He’s vulnerable to big servers, and his own serve, especially with his back, is less of a weapon than it once was. He’s particularly vulnerable to tall players, who can handle his jumping shots. And he’s vulnerable to players who have nothing to lose. In the past three years, low-ranked, unknown men — the same kind of men who were once terrified even to step onto the same court as the great Nadal — have had an eerie ability to go for the lines and zone.

Kyrgios checked a lot of boxes. He’s 6-foot-4. He has a huge serve and surprisingly good reflexes, and easy, fluid strokes. He isn’t afraid. He’d saved nine match points against Richard Gasquet in the second round. Like the other players who have had the most success against Nadal, he had nothing to prove. He is still a teenager, and he is playing in his first Wimbledon. He spends most of his time on the Challenger circuit.

But Kyrgios is different from the players who tend to give Nadal trouble. He projects a faith not only in himself but in the future. He hit 37 aces and 70 winners — 70 winners against Nadal! Some of his shots were stunning, thrilling, irresponsible — but also hit with an ease that projected more confidence than cockiness. At 3-3 in the second set, he flicked his racket behind his back and through his legs and struck a delicate tweener drop shot. What was even more remarkable to me, though, was his reaction. He raised his arms in mock triumph, like I do on the public courts when I catch a lucky net cord. But then he turned around, and he wasn’t smiling. His mouth was set. He was ready for the next point.

He came in hyped and justified the hype. He hit service winners at the biggest moments. He moved catlike; he took the ball as if it were a bird. He was surprising everyone but himself. He didn’t have the air of a guy who was playing the best match of his career. He made me think just the opposite: He was playing the kind of match he might play throughout his career. Kyrgios is already playing for posterity, I thought, and Rafa looks tired.

You watch enough tennis — you watch enough of anything — and you recognize patterns, you imagine symmetries, you look for narratives, you see cycles. You know that people age; you’re aging yourself. You remember Rafa beating Federer as a teenager at the 2005 French Open. Federer beating Sampras. You anticipate the end of things and declare new beginnings.

But maybe there’s a better way to watch. Maybe the best thing to do is to let yourself be surprised.