https://www.wired.com/story/mathematician-terence-tao-cracks-a-dangerous-problem/ > Experienced mathematicians warn up-and-comers to stay away from the Collatz conjecture. It’s a siren song, they say: Fall under its trance and you may never do meaningful work again. > The Collatz conjecture is quite possibly the simplest unsolved problem in mathematics—which is exactly what makes it so treacherously alluring.