People very often - I'd say the more modern they are, the more often - do not allow each other to act naturally or spontaneously.

You turn up your nose when someone burps or farts. You frown when someone laughs in a sad situation or cries in a supposedly normal moment. One forbids any behaviour that reflects an authentic expression. Such are head-births of those who have been suppressed in order to restrain their own spontaneous expressions of a physical or verbal nature. Any group that punishes spontaneous human expressions of the individual as a violation of the rules puts everyone in a straitjacket.

One is irritated when others smack at the table or make other noises. There is a rule that you are not allowed to get up from the table until everyone has finished eating. And that's where the children sit, with stomach aches because they suppress their flatulence. In the classroom, they may sit all day with stomach aches and also wherever people share the room with people. Not even outside, in nature, around the campfire, they dare to finally give their bodies the freedom they need.

Over the many years the body hardens, forming knotted and solidified body parts, the constant tension takes its toll. One suffers from intestinal problems, stomach ulcers and so on.
And the mind craves for free speech as well.

Every creature on earth builds its nest, digs a cave, only man, poor man, has nothing to rest his head on.