The headline at Mental Floss refers to "interpretations" of Shakespeare's works, so I expected them to tell us how The Lion King is based on Hamlet and 10 Things I Hate About You was an interpretation of The Taming of the Shrew, which we all know by now. But this list goes into some deep thinking that people have been doing about the relationships and motivations of Shakespeare's characters that aren't spelled out in the stories, but extrapolated from small clues in the scripts. Yes, some people have more time on their hands than you or I do, but these theories do make sense.
For example, why does Iago so badly want to ruin Othello's marriage? Was it because he himself desired Othello? That makes more sense than just retribution for a professional slight. Was Ophelia pregnant? And MacBeth's soliloquy -the only long passage from Shakespeare I can still recite- were those words from one character or two? Then there's the Unified Antonio Theory. Read up on ten intriguing theories about Shakespeare's characters and plays at Mental Floss.