- Squirt sunscreen into both hands.
- With hands, attempt to rub suncreen over your entire back.
- Swim in the ocean for 4 hours under a hot, blazing sun.
The resulting red blotch in the middle of your back will look almost exactly like Pangea as pictured in school textbooks. It also will hurt a lot.
The lesson? Unless you can detach your shoulders from their sockets, you cannot cover your entire back in sunscreen.