Jane and David are similar to you. They are about the same age as you and have about the same educational level and work experience as you. However, Jane and David differ from you in one very important way:
Jane and David have never seen toothbrushes or toothpaste.
In fact, Jane and David have never seen brushes or tubes of any kind.
Write instructions telling Jane or David how to get toothpaste on a toothbrush.