Rafael Nadal is having the time of his life

It is beginning to seem unfair. Not just how cavalierly Rafael Nadal has returned from chronic knee trouble to pound so many worthy tennis opponents; how Monday night's four-set U.S. Open championship victory over No. 1 Novak Djokovic was Nadal's 60th in 63 matches this year.

More than the striking results, especially for a man who spent seven months away from the pro tour, is how eagerly Nadal embraces all challenges and continues to put himself through the training grinder.

The Nadal disposition -- whatever it takes, however it takes -- was evident again against the flexible, tireless Djokovic, as each man would temporarily dangle over the precipice of deep danger, then scramble and pull himself back to relative safety.

Where hard courts for years were Nadal's biggest trial, both competitively and physically -- it wasn't until his sixth Open that he got past the quarterfinals -- the surface now seems nicely utilized by Nadal to enhance his topspin forehand, the sport's nastiest.

He has won all 22 matches on hard courts in 2013; through seven dominant Open wins, he lost only two sets. Though he never has served with fearsome velocity, he won 95 of 99 service games in the tournament.

"I like hard court," he insisted during the Open. He tweaked his serve to better suit the surface, moved a bit closer to the baseline, worked at shortening points.

"Look at Nadal," said Patrick McEnroe, whose many tennis hats include serving as director of player development for the U.S. Tennis Association. "I mean, the guy is an incredible example of someone who, as good as he is, all he wants to do is try to get better.

"Obviously, he likes to win, too. But to me, that's not his primary intention. For some great players it is; that's fine, too. That worked for Jimmy Connors and Peter Sampras and people like that. But I think Nadal enjoys the process as much as anybody."

At 27, Nadal has won 13 Grand Slam events, closing in on Roger Federer's record 17, with an unprecedented eight French Open titles. The $3.6 million he earned with Monday night's victory put his career prize money at more than $60.5 million.

Yet, as old champ Connors put it, "Nadal plays like he's broke."

His style is all charging-bulls-at-Pamplona, his businesslike on-court countenance typically features a little snarl. But he repeatedly has assured that he is having the time of his life, his career path riding on a rainbow.

"You need to work hard," he said of his outlook, both before and after his knee rehabilitation knocked him out of last year's Open and January's Australian Open. "You need to work with the right attitude every day. You need to be ready to suffer, to enjoy the suffering and to be able to change the situation.

"When you are in a low situation, you are able to work to change that dynamic, because you really feel the love for sport, the passion for sport. After overcoming a tough situation, then you are ready to compete better than before. I love the sport. I love the competition.

"I love the sport like a spectator. So to have a chance to go on court in big stadiums that I saw on the TV when I was a kid, always is really special for me. So I feel very lucky and very happy to be back on the tour and playing well again."

He is enjoying the suffering, he said. Which may seem a bit unfair to all those opponents he is keeping in distress.