Today is my girlfriend's and mine one-year anniversary. We went to dinner and to see a movie, and exchanged presents. Your 'Unexpected Shapes' video came just in time for me to use it today. I did the whole act during dinner. I started with the content of the extra video: the 'impossible' move of the paper flap from one side of her hand to the other side, with her eyes closed. I then did the rings/squares/möbius/hearts routine. She loved it! To finish it, I repeated the impossible flap move, only I also placed her present on the table while her eyes were closed.
We are both students of artificial intelligence and are fond of maths, so these tricks are very enjoyable to us.
I thought you might like to see how, indeed, this piece of mathematics can be applied in practise. I attached a photo showing the end result.
Cheers and keep up all the great work,
The videos in question...