Collatz Conjecture is the conjecture that all numbers will eventually reach one if they are put through a repetitive algorithm where if the number is even you cut it in half, and it is odd, triple it and add one.
Despite being a relatively simple algorithm, it has never been proven to be true, despite all numbers being tested eventually reaching one.
The numbers have a tendency to follow a hailstone pattern where they rise and fall for seemingly no reason. It may seem random, but it is actually chaotic, where you can't predict where the numbers go by approximating but you can predict them one at a time exactly.
Monty Hall Problem: https://www.youtube.com/watch?v=SG9mAiGUdJE
Why Istanbul is the Most Strategically Important City In The World: https://www.youtube.com/watch?v=uxWdmi4vsaU
Why Toy Videos get so many views: https://www.youtube.com/watch?v=m0Q5jO8I59w