Celebrities being friends is not unusual. What is, however, is how many celebrities from totally different fields (or even time periods) knew each other before they got famous.
History is fraught with inexplicable artistic trends which seem silly to modern-day people. But if you look into it, sometimes there's are very good explanations for them.
Nov. 4 is Election Day in America, and there's a good chance you'll wind up making your choice based on some stupid/trivial factors they're not even aware of.