Here's a funny article about a parent showing off on a bus by bellowing at his "taciturn" four-year-old.
Dad: Now Benjamin, would you like to keep playing I Spy or shall I teach you to count past 100?
Dad: Okay. Now you already know how to count to 100 and it’s surprisingly easy after that. What do you think comes after 100?
And so forth. The other riders are irritated. They look away, sigh, snap their newspapers, but they don't know how to shut this guy up.
For future reference, here's what you do: Identify another rider who sits not too far away and looks fairly irritated, and engage him/her in loud conversation, as loud as the obnoxious dad: "EXCUSE ME. DO YOU MIND IF I ASK YOU WHERE YOU GOT THAT SWEATER? I'VE BEEN LOOKING FOR ONE THAT EXACT SHADE OF ORANGE - I HAVE A PAIR OF TAN PANTS AT HOME..." This works when people are shouting into their cell phones too. I used to feel vaguely irritated at being tricked into being quiet while somebody else carried on private conversation in public, but not anymore.