I'm not sure this helps to become a deep thinker, but just for the active recall part, I keep all interesting browser tabs open (and also bookmark them). When

I'm not sure this helps to become a deep thinker, but just for the active recall part, I keep all interesting browser tabs open (and also bookmark them). When I have too too many tabs open I'll save the entire set using a bookmark manager, then start afresh, go through the previous tabs one-by-one, and reopen the really interesting ones, and do a bit more research around them. I'm not sure this really counts as a rational or sane process though!