I really hate the whole concept of body language. It's just basically you unconsciously expressing yourself and even then, it doesn't paint an accurate picture of what you are truly thinking or feeling. Some people are oblivious to it while others are extremely sensitive to it.
When I was a kid, I got in trouble multiple times for "displaying inappropriate body language to teachers" and I never knew what I did wrong.
recognizing something as a word and active concept kinda leads to obsession; so people who think of the term body language are more likely to obsess over it, kinda like how a noise doesn't bother you until you start noticing it.