This is a true confession. Last week I was walking towards the squash court for the fourth day in a row—two of them after 2+ hours of tennis—and my left knee started clicking or popping. No pain, just sounds. I hit squash balls that day and the next, but still just tightness. I have no recollection of any twisting or sudden jarring that would have done ANYTHING.

I spoke to a doctor who said I was describing bone to bone rubbing, a lack of fluid, and advised me to take glucosamine, which is over the counter. He said it could be the onset of arthritis, didn’t sound like a tear. I looked up some quad exercises that might help.

The clicking was intermittent, and over the next few days there was some serious soreness.

So I started worrying A LOT that maybe my super workout, 2-4 hour sports days might end. Maybe I had Lyme disease. Maybe I wouldn’t be able to play tennis into my nineties, or even my eighties. Damn! Just when I was improving. Could I have arthritis, a torn knee?

I’ve spoken to friends going crazy about not being able to exercise for weeks after leg breaks from skiing. I’ve talked to people who have had clicking joints for years and just took it and the pain in stride (“I don’t even feel it any more. I could never be a ninja and sneak up silently on anyone.”) Others tell me that they are always in pain from sports exertions and injuries. And I hear countless stories at the tennis club about players of all ages who have given up the game, because the risk of serious disability is too great for their hurting knees and shoulders.

Then I spoke to friends who have—or told me—about illnesses that are so serious that they might die. The fear and reality these people live with each day sounds terrible. They go to hospitals and see doctors weekly or monthly. I can’t imagine what that is like, even though I have spent months in a hospital recovering from hepatitis and jaundice in Korea, was flown back to the States on a stretcher, and took weeks of recuperation, before I could walk one block.

So now I feel great shame that I am upset over not playing tennis another 5-15 years. Of course Life is NOT fair. And we have to play with the cards that it dealt us. Some are poor, like bad genes. Others are crappy, like accidents that no one ever thought about or were one in a thousand or one in a million chances we would be hurt. Wrong place wrong time. Or OK place, but still wrong time.

How can I moan about it? But everything is relative.

I knew someone who was making over a million dollars a year many decades ago. I was making less than $35,000 then. Yet he was hanging around with tycoons acquiring over $50 million a year. He felt poor. He was frustrated. He felt inadequate.

A friend told me about an acquaintance who had inherited $600 million, but was depressed in 2009, when his fortune declined by a third. So he only had $400 million to his name. Laughable to me. Misery to the rich guy.

How do we resolve these attitudes? It’s like being caught in two or more worlds. Glad that I can play at all…have the time, don’t have to work every minute, have the health, live near a court. Others are sick, working like animals at my age, or are dead. I should be grateful for any level of play and decent life. Even if I can no longer run safely around the court.

But then there is the other world, where I want to keep going, improve, have the greater satisfaction that comes with prowess, cardio, health, more skill. It’s not enough just to be alive and healthy. I want to push and grow and accomplish. Greedy for more, lusting for continued success.

Maybe it is just built into our DNA. A human survival instinct. As long as we’re alive, it’s not enough to just watch TV on a couch or the ocean from the beach. We need the challenges and reaches, the competition and grasping for achievement. What do you think?