Thinking. We all do it (sometimes); often about the wrong things. The times we choose not to think are usually the times we need it most: when it's something we need to decide or take responsibility for. With so much "knowledge" out there today, many people suspend their ability to think independently, thus allowing it to atrophy, and then wonder why they aren't getting what they want. It's because you're allowing other people to think for you. Bad idea.