Or that they are supposed to be making notes on worksheets they've been given that are tucked into clipboards with pencils that have chewed off erasers. And that they must come to a dead stop to make those notes in the middle of a crowd of other school children that has a current that sweeps even the adults away quickly.
It isn't the bumpy, slightly stenchy, hot bus that makes even the most iron-bellied passengers feel nauseous.
It isn't that there is always one half of a seatbelt missing so that one of the three students squeezed into the bus seat cries when she has to sit with other kids, alone, or worse, the chaperone.
It isn't that the hours tick slowly, and that there are always too many hours to spend at the zoo, the museum, listening to a tour guide use that annoying baby-talk voice he thinks will engage kids who are in no way engaged.
It isn't the gripping fear that one child in your care will flee, vanish, pause momentarily, wander off, accidentally cling to another group or get pulled under in the current of kids in the ape house, backstage at the theater, while boarding the bus -- and will be gone. Like, REALLY GONE.
And it will be the child who has been whining, kicking, bullying, accidentally-on-purpose poking at your boob, pouting, talking incessantly, causing you to spontaneously think without thinking, "Wow, it's so gloriously quiet" in the split second after you realize he's not there.
It's not the guilt that follows that thought. Nor the panic after that. Not even the deep, ojai breathing you learned in sweaty yoga, therapy, Lamaze class, during the worst finals test ever to keep yourself just barely calm enough to see your way through a crisis and FIND THAT KID.