A second thought: Basic hygeine
I think we should all re-examine the bases of our basic world view, at least once in our adult life. Here's why: Have you ever deeply studied a complex topic, and, taking each fact to it's logical conclusion, built a chain of fact and logic that ends with a particular firm conclusion? Five years after your studies, you still hold to the conclusion, but can you recall the circuitous route you took to get there, step by step? All of us hold firm (not unbreakable) conclusions on several topics, without remembering all the details of how we reached the conclusion. The "details" - that's my interest, on many subjects. Details enough to convince myself that a certain conclusion is worth taking up.