The last time I saw my son, he was playing with a Rubik's cube, but didn't know how to solve it. Somehow in my absence, he has mastered the thing, and now enters speed championships, solving it in about 15 seconds, which is pretty good, but not good enough to win.

So I asked him how he learned how to solve it. I had learned how to solve the first couple of rows, but never successfully memorized the algorithm for solving the last row--but this algorithm isn't the one used by speed cubers in any case. He told me that he first learned how to solve it the slow way on the internet, but he really wasn't able to say how he learned to solve it quickly.

He told me that he actually figured out how to solve a different puzzle--one composed of tetrominoes that have to be fit together into a square--and solving this somehow helped him figure out how to solve rubik's cube quickly.

I don't see the connection between the two puzzles, but there it is.