Uncomfortable showing emotions
I suspect a lot of us men will relate to this (without sounding sexist I believe it is predominantly a man thing). We were always told “Real Men don’t show emotion” and “Keep a stiff upper lip” We often equate showing emotion to weakness. Maybe it goes back to our caveman survival instincts - face down the wolf rather than showing fear which may make it attack. Luckily we don’t have to face many wolves nowadays, so perhaps we should let our feelings out!