Feeling feelings can be hard for some people. If you put up walls young, you’re afraid of your own emotions because they’re immature emotions. You don’t know how to deal with them as nobody taught you how.
So what do you do when you start to feel? You use various tricks to shut it down quickly.
Also what might make it difficult tor some people is their empathy. Low empathy can also mean they even have low empathy for themselves – literally “not in touch” with their own feelings.