Rich kids should go to public schools. The mayor should ride the subway to work. When wealthy people get sick, they should be sent to public hospitals. Business executives should have to stand in the same airport security lines as everyone else. The very fact that people want to buy their way out of all of these experiences points to the reason why they shouldn’t be able to. Private schools and private limos and private doctors and private security are all pressure release valves that eliminate the friction that would cause powerful people to call for all of these bad things to get better. The degree to which we allow the rich to insulate themselves from the unpleasant reality that others are forced to experience is directly related to how long that reality is allowed to stay unpleasant. When they are left with no other option, rich people will force improvement in public systems. Their public spirit will be infinitely less urgent when they are contemplating these things from afar than when they are sitting in a hot ER waiting room for six hours themselves.

It wouldn’t be so bad, if the line still moved. But it doesn’t. It stops, every time a group of people with Flash Passes cut to the front. You used to be able to go on, say, three or four rides an hour, even on the most crowded days. Now you go on one or two. After four hours at Whitewater the other day, my daughter and I had gone on five. And so it’s not just that some people can afford to pay for an enhanced experience. It’s that your experience - what you’ve paid full price for - has been devalued. The experience of the line becomes an infernal humiliation; and the experience of avoiding the line becomes the only way to enjoy the water park.

An advanced city is not one where even the poor use cars, but rather one where even the rich use public transport.

“There’s very good evidence” that high-intensity interval training provides “many of the fitness benefits of prolonged endurance training but in much less time,” says Chris Jordan, the director of exercise physiology at the Human Performance Institute in Orlando, Fla., and co-author of the new article.

Interval programs based on cycling, walking and running come with a downside, however: They improve overall fitness and health but do little to improve muscular strength other than in the legs. By contrast, the New Scientific 7-Minute Workout does more than build the large, obvious muscles that most of us can name-check, as Mr. Verstegen puts it — the quads and glutes, for example; its exercises also engage smaller, often overlooked muscles in the back, abdomen, shoulders and hips that, when neglected and weak, contribute to back, neck and knee pain.

Do air squats as long as you can until your leg freezes and you topple to the ground. Then get in pushup position and do as many pushups as you can until seven minutes have passed.