What things don't usually care about, but if they are lost, they will be very sad?

It is common for me to lose things. I can't find it when I use it. I don't know when it came out. The deepest impression goes back to my childhood. At that time, children in rural areas may only have one or two toys in their childhood, such as baby. I have a plastic doll with a round head and a round belly. I don't remember if my father bought it for me. I cherished it at that time. Basically, I can hold everything without leaving my body. Suddenly one day it disappeared. My mother searched every corner of the house, just like in the air. I cried for a long time. Later, I went to my neighbor's house to play and saw my toys. I'm sure it's my doll, but I don't want it back, because my neighbors insisted that they bought it and didn't want it back in the end. The loss of that toy made me sad for a long time. For so many years, there is only one thing I have kept in mind. Later, I had other toys, but I don't miss them now.