I think the reason for locking the cupboard is most inclined to everyone's own personality. People who often like to lock their cabinets are generally very organized. If they don't lock the cupboard or even sometimes the door is always open, it must be careless and irregular. When I was in college, I locked my locker every day, not for fear of losing things, but I just thought it was a matter of course, but I usually had two keys, and I would bring one myself and put it under the mattress for the convenience of my roommates. Actually, our relationship is very good. I often open their lockers to get things, and when I'm away, they will also use the key to open my lockers to get things.