And some of the voices and accents you hear, by gosh. There are the huskies, gravellies, squeakies, shouties and sighees. And then there are the thick Kiwi accents, the foreign ones, the unintelligible ones. The list goes on.
Interestingly, when, for instance, you hear a husky-voiced woman talk in a strong Kiwi accent for a good 10 minutes without turning round to look at her, you often presume you know what she looks like. You have a pretty good idea she's, let's say, a mid-twenties, blond-haired, fake-tanned, short-skirted, big-busted real estate agent. Then you take a look at her and your conjecture couldn't have been further from the truth: she happens to be a 55-year-old, skinny, little, nervous librarian with a hairpiece. This is called the case of the face not corresponding with the voice, and it happens most frequently on buses and at sporting fixtures.
During these ignominious situations, you really get put through the grind. In addition to being stuck, you're closer than humanly comfortable to some of these careless chatters, so not only do you get the full force of their voice and conversation, but the full force and smell of their breath.
So, if you don't mind other people's business, be on the listen-out, for "careless talk" only ever "costs lives", as the axiom goes. "Careful listening-in", on the other hand, will only cost you your peace of mind. But, hey, enjoy!