If you can afford to eat out with your friends you can afford to eat a bit better and have more fun.
"If you can afford $X, you can afford $X+5" is a dangerous rule to live by, and terrible advice. Obscuring costs is not an upside unless you're very sure that your reaction to them was irrational to begin with.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.