Great video. And great subject.
I first encountered the 555 when I built a random number generator, decades ago, epochs ago. It pulsed at a few MHz into a super-simple counter. The counter went "1, 2, 3... 14, 15, 1, 2, 3... ". But all you saw at the output was a blur, until you broke the connection between the timer and the counter. Then a number magically and randomly appeared.
The best part was building it. For the sake of debugging, I initially used a 33 mF timing cap. This meant that the 555 pulsed a about a Hertz. I watched the counter count up and reset. When I broke the connection the counter stopped.
Then I changed the value of a capacitor (something pF) and a deterministic system that did essentially nothing, became a random-like system that did magic.