I was surprised at how rich and complex the subject of humans cooking their food turned out to be. The book "Catching Fire" by Richard Wrangham (not the Hunger Games volume 2 by the same name) explains the benefits we get from using heat to chemically change our food. Of course, the subject of cooking and food preparation is rich and involves social occasions and cooking shows and contests and whole careers as chefs.
Having been alerted by Prof. Wrangham to the very widespread results of stoves, microwaves and kitchens and who cooks for whom, I noticed another aspect of human life that you might think we couldn't manage but we do: toilet training. I notice that when we speak of a pet cat or dog, we ask if the animal is "toilet trained" or "house broken" but with our infants we often speak of "potty training."
Here in the north, we have plenty of lakes. We usually we have parks around some of them, nice green grassy lawns around blue, sparkling lakes. These are attractive to geese, such as the large Canadian geese. Nice birds but poopy. (We tend to use the word "poop" for human excrement with children and in nice or semi-nice company and to reserve the word "shit" for an expletive to label something as unwanted, unpleasant and stinky.) When you seen how often one or another of the birds empties their bowels, and you think of 8 billion humans, larger animals for sure, you might not believe that we could learn to control our own bowels and avoid the goose-yard syndrome. Not with so many of us and such a recurrent need in our bodies.
But you know the answer: Bathrooms! Very often, a 'bathroom' is a place to use a toilet, not to take a bath. We also use the term RESTroom, even though if we want a rest, we don't normally go there but to a different room. Sometimes, the term "gentlemen's" or "ladies'" is used without further explanation. We say "Where's the john?" or the latrine or the "head". Frequently, if we get close to a waiter or waitress, they will guess our question before we speak and point in the right direction.
You might guess that the whole species would be unable to collectively arrange for bodily evacuation to be as controlled as it is, just as you might guess that we would be unable to teach such a large portion of our group to use silverware or chopsticks, to read and write, and to generally learn to behave in the restricted ways we think of as mannerly, polite and civilized.
Restrooms are really in the news right now as we wrestle with our long-standing idea that men and women should have different bathrooms but now many people are all confused about where transgendered people should go. I have used large bathrooms in a college dorm during a week-long meeting of the Friends (Quakers) General Conference with adult men and women going in and out of the same bathroom. It was a little odd at first but we managed very well. There weren't that many dorms and this one was set for those willing or in need of avoidance of scented products due to allergies. Nothing to do with transgenders.
Once I watched Candid Camera show prospective renters an apartment. It took the interested parties a moment to realize that there was no bathroom in the apartment. That is not a big problem in some situations. In the novel "Excellent Women" by Barbara Pym (1952), British people in a building of apartments and rented quarters shared a bathroom among renters of both sexes. They expected to and so did people in similar quarters in the US.
If you are interested in this subject, you might want to look at "The Big Necessity" by Rose George.