Tower of Hanoi: the move after which everything tangles
Four disks, three pegs. Move the pyramid from left to right. I made six confident moves, and on the seventh realised I no longer remembered why I had put the second disk in the middle. Twenty more moves of untangling followed.
The free peg is a tool, not a warehouse
The rules of Tower of Hanoi on igrasu.ru fit in two lines: move only the top disk, never a bigger onto a smaller. The perfect solution for four disks is 15 moves, and the demo mode plays it in full.
The beginner mistake is always the same: using the middle peg as storage. Park two disks there “for now” and they block each other. The middle peg is not for storing but for turning: the biggest disk travels right only when both pegs beneath it are free. Before each move ask: “is this disk here because the finale needs it, or because I was too lazy to think?”
The one-glance rule
Before moving, look not at the disk in your hand but at the biggest one still away from home. Everything else serves its relocation. Once your eyes switch from trifles to the main disk, the wasted moves disappear on their own.