This article is in a superposition of tongue-in-cheek and tongue straight in the mouth. (That's a Norwegian expression meaning "to concentrate on something difficult".) If you read it, please report your experimental observation of which it is, so that we can determine the amplitudes of the two states. However, I am actually making a serious point: Why do we have this non-optimal norm, and can we change it?
Gyms, at least the ones I've been in, seem to have a norm that each user should wipe his own sweat off the machine he just used. This is obviously inefficient. Consider that there are two kinds of users: Sensible, rational people (SRPs) who don't give a damn about other people's sweat on the machine; and finicky fussbudget frumpy failures (4Fs) (names chosen at random out of a hat, and completely unrelated to my own opinion on the point) who are too precious to have anyone else's sweat in their immediate vicinity; it's not as though they're going to shower after their exercise, right? Anyway. Under the existing norm, everyone has to clean once per machine use, but only the 4Fs are getting any utilons. Clearly, if we switch to a norm that everyone optionally cleans the machine they're about to use, then the SRPs are saved some work, while the 4Fs still get to use clean machines. This is an obvious Pareto improvement. Moreover, it's also a Nash equilibrium (and, incidentally, the current norm is a puzzling failure of the usual rule of thumb that social arrangements are Nash equilibria - why have we chosen this particular activity as one where we put effort into pushing people away from the equilibrium?) since nobody can improve his situation by cleaning the machine after using it, or failing to clean beforehand.
Please spread the word of this obvious improvement in gym-users' quality of life! Also, please push society towards the Nash equilibrium by defecting from the current norm: Either clean your machine before, not after, using it, or else don't clean it at all. If anyone challenges you, give them a quick lecture on economics - this has the added benefit of making you popular with the opposite sex.
Some possible objections:
1. My mother taught me to clean up after myself.
And imagine how much more pleasant your childhood would have been, if only you'd known about Nash equilibria and Pareto improvements! However, not all is lost: You can still try to convince your SO or roommate that the one who cares most about mess should be the one to clean it up.
2. My utility function has a term for not making others do work.
Also, apparently, for signalling your concern for others. The total amount of work done is rather less in my proposed new equilibrium. Suggest you update accordingly.
3. I prefer cleaning up my own sweat to cleaning that of others.
Have you considered the benefits of self-modifying to be more masochistic? Today's society offers all kinds of opportunities for turning yourself on, if only you could take advantage! This could actually be more efficient than taking a pill that makes you bisexual, since you can only sleep with so many people in one lifetime anyway. Repeat after me: Thank you for making me clean the machine, Master! Please may I clean another? There, do you feel the surge of hormones?
4. If I have to clean the machine, everyone else should too!
Until the rest of society has self-modified to be sufficiently masochistic to derive pleasure from your dominance, you should not attempt to impose it on them. This aside, have you considered the benefits of suggesting suitable punishments for anyone who doesn't clean their machine? Aren't they being rather naughty? Many exciting encounters may result from this handy ice-breaker!
5. My gym doesn't have that norm.
Excellent! Please spread the word. Today your gym, tomorrow mine!