Answer:
Prior to smartphones, people used this to record their lives.
What is the center of gravity?
I'm a small ring shaped fried cake, often with bavarian cream or fruit filling, and sometimes covered in icing and sprinkles.
The negative hero in each story
It belongs to you, but other people use it more than you do. What is it?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?