Nothing screams "party animal" quite like whipping out the Chinese Remainder Theorem at a social gathering. The textbook suggests you can determine someone's exact age just by knowing the remainders when divided by 3, 4, and 5. Because apparently, normal people at parties are totally down to do modular arithmetic instead of, you know, just asking "how old are you?" The facepalm reaction is spot-on because the textbook's definition of "real nerd" is someone who thinks party guests will enthusiastically participate in number theory exercises. Sure, the math works (since 3, 4, and 5 are pairwise coprime, you can uniquely determine any age up to 59), but good luck finding anyone who won't immediately walk away when you start asking for division remainders. Fun fact: This is actually a legitimate application of ancient Chinese mathematics, but using it as a party trick is the mathematical equivalent of bringing a graphing calculator to a bar. Technically impressive, socially questionable.