Tezuka is an old man when he finally discovers the reason why Ryoma plays so well.
Actually, he's not an old man, but he's older, and everyone is an old man compared to Ryoma. Sometimes he's ageless too, and then ages fluctuate, so that Tezuka at one point swears Ryoma is as old as the game of tennis, and at another point he swears Ryoma is the most immature child ever born. Tezuka knows Ryoma's age. Three years younger than Tezuka's age, twelve when Tezuka was fifteen. But sometimes it's hard to believe Ryoma's that young; other times he just can't be that old.
Anyway. Tezuka is an old man compared to the Tezuka of Seigaku and an old man compared to Ryoma when he finally discovers the reason why Ryoma can play tennis so well. Talent and genius all figured in there, of course, and the natural born need to succeed and dominate and win, but the truth is that Ryoma doesn't believe in reality. When Ryoma gets on a tennis court, he's hard pressed to remember that rules of gravity or physics actually exist, and that it's just impossible for him to do certain things. To Ryoma, on a tennis court, anything is possible. He's not bound by the expectations of anyone, just by himself.
It's why no one can take their eyes off Ryoma when he plays. Everyone loves the person who can make anything possible. Ryoma does that, and does it well, and makes it look simple, so simple, in fact, that you think nothing of it until he pulls it off again. And again. And again.
Fuji was absolutely right about Tezuka being a pendulum. At first he could improve greatly, and then greatly still, and learn how to use his right hand, and then revamp his left hand having had to wait for it to be treated, and then he learned how to play tennis again, properly, but in the end, Tezuka's improvement had to stop somewhere, and the pendulum had to stop ticking. It did, and so did Tezuka's improvement. He had a limit to reach. It was a high limit, infinitely higher than most players' limits, but he had one. It was a solid limit. Tezuka could hit it with full force. Eventually he got used to it and the idea that he would never get through it.
Ryoma, Tezuka knows, has a limit too. Everyone does. But as if it were possible, Ryoma's limit is even higher than Tezuka, and Tezuka doesn't know what could possibly force Ryoma to hit it except Ryoma himself.
It all comes back to Tezuka when he turns on the TV. He had started to forget all about everything, had even started to doubt whether or not the memory of Ryoma had been real, had been avoiding all mention of tennis on the news since he quit, when he turns on the TV and there is Ryoma, not even sweating as the reporter interviews him, obviously glowing in the aftermath of a game. Tezuka can't hear what Ryoma's saying because the sound is on mute, but Ryoma's image is real in front of Tezuka. It doesn't look as if he's grown up at all. Tezuka has a feeling Ryoma will always be short.
He can almost hear Ryoma say, "Mada mada dane," even though one look at the crowds and the reporter assures him that the interview is being broadcasted from America.
When Fuji enters the apartment with an armful of groceries, Tezuka is in front of the TV, his fingers lightly brushing the image of Ryoma on the TV, gathering static into his hand. Fuji puts down the bags and stares at Tezuka for some time, the winter air cold off of his coat, and then he says quietly, pulling off his gloves, "I guess you still can't forget him, after all this time, right?" Tezuka is silent for a while, but then he reaches for the remote and says, "Ah." Fuji puts his gloves carefully on the kitchen table and starts to unbutton his coat, says, "He hasn't lost his touch."
It isn't until Fuji's hanging his coat in the closet and folding his scarf away that Tezuka finally works up the nerve to turn off the TV. Then the image of Ryoma's face still burns on the black TV screen, so Tezuka has to stare at that as well, until Fuji makes a little sound somewhere in between discomfort and regret and worry, and Tezuka realizes exactly where he is.
The truth is Fuji is right. After all these years, Tezuka is still a pendulum, and it's not so much that he can't forget Ryoma as it is that he keeps remembering Ryoma. Tezuka can't move anymore, not from the silent frozen empty motionless place he's put himself, and that's all there is to it, less complicated than what Tezuka would like to believe, and more complicated than the image of Ryoma will ever be.
Tezuka thinks to himself, I'm too old to be chasing the ghosts of the past. It's all over now. I'm too old to be trying to do everything I did when I was younger. I'm too old to try and catch up to him. When he kisses Fuji later, he can feel the static from the TV screen in his fingers, still, and he thinks, I'm too young to feel like this, too.