I don't know man, very often sophisticated problems require recursive thinking (even if you don't write it so later on) to be able to see similarities in sub problems. Just last week I had to resort to this to flatten-index json files. I started confused and then made an inductive leap and the solution unfolded itself (no pun intented) as a two-liner.

It's way beyond brain-teaser for me, it's the sharpest tool I know of.