Chewing is instinctive.
We actually pay money for chewing gum, a product whose main purpose is to provide us with gratuitous activity. But apart from recreation, chewing is important to the proper processing of food. That is, except for people who try to gum their food when they don’t like what they’re eating.
Speaking of not chewing, there’s also a product called chewing tobacco. It’s not meant to be chewed — only crushed with the teeth. Seemingly, the concept of chewing is ambiguous, but don’t chew me out about it.
Chewing must be important, or why would millions of cows worldwide spend all day chewing their cud? Come to think of it, cows have too much time on their hooves anyways. It’s an animal thing — just try to get your pet to stop chewing.
In addition, chewing can be a metaphor for thinking things over. It even can be an addiction, like when someone chews ice — without regard for the dental bills.
Thanks for the opportunity to chew the fat with you. Keep calm and chew on. (By the way, you have spinach stuck between your teeth.)