Overthinking can feel terrible, leading to anxious memories, stressful hypotheticals or negative thought patterns. Your brain goes into complete, often irrational overdrive. Want to go to sleep? Your brain offers you an embarrassing situation to mull over instead. Your boss sends you an email asking if you can talk? You immediately start thinking of all the things you did to possibly get fired. If this sounds totally familiar, take heart in the fact that you’re not alone.