I've, of course, heard the phrase "don't judge a book by its cover." Every single time I've heard this, it's been in the context of underrating someone or something - the "cover" doesn't look very nice, but the book is. Recently, I've learned that the flip side is also true: sometimes a book's cover is much nicer than the book itself.

This might be obvious, but it wasn't to me. This manifests in lots of interesting ways - one might set themselves up for an interesting story, only for it to be a dud, or maybe the cover is intimidating, but the story isn't. The lesson is still the same - don't discredit (or credit) any person or thing before you learn more. Though, as counterintuitive as it might sound, I think this lesson is harder to learn.