I'm fond of saying that "there's always one in every group that ruins the fun for everyone else. If you don't know who that person is, that means that it is you."
Maybe it's just me, but I've found that the above is true. No matter the size of the "group," there seems to always be at least one person who ruins the experience (whatever it may be) for everyone else. Why is that? Am I the only one this happens to?