We all know how Spider-Man turned from an "I look out for number one" opportunist into a "with great power comes great responsibility" hero, right? (If not, well, after 50 years, I'm not going to slap a spoiler warning here.) But it was all about Spidey letting a crook get away who later killed his Uncle Ben. For quite a few years, though, Marvel might not have wanted you to think that.