Why don't parents like to see their children put their hands in their trouser pockets when they walk, but like to take them out? Personally, I think it's in my belt!
When I was very young, my father told me that it was not good to put my hand in my trouser pocket. There are two important things, 1. When your feet or shoes trip, you should reach out from your trouser pocket to support your body's center of gravity. Slow down. If it is serious, your head will be broken. 2, when greeting people, I saw a person, and now it is impolite to take your hand out of your trouser pocket.