16. Identical twin here; my brother has a birthmark on his foot, and for the first 2 years of life we were basically shoeless. It was the only way to tell us apart… After it became obvious that we needed to wear shoes, my mother began color coding our clothing. To this day, red is my favorite color and blue is my brother’s.
17. I mixed mine up within 8 hours of birth. I kept their hospital bracelets on for a long time and then could always verify by the shape of their belly button scar.
Now I can kinda tell but I also have to ask them sometimes.