I have ADHD , so this is my experience , but it differs for everyoneTrue Symptoms Constant fidgetingtapping hands or feet The need to walk aroundget out of your seat Having trouble focusing or memorizing things Blurting out inappropriate things without thinking . Impulse control was a massive issue for me , and I would often say or do idiotic things without thinking it through . Usually people who knew me could tell when I just wasn ' t thinking , and when I was being a dick . Excuses Laziness There ' s a difference between someone not being able to focus on something , and someone outright being lazy and not wanting to do it . I wouldn ' t get things done because I would start , but get sidetracked by something else . Intent This one is a big one . If I hurt someone ' s feelings or broke a rule , usually it wasn ' t intended to be malicious , I would just speak without thinking . Usually , when people with ADHD get in trouble , there is a lack of malicious intent . Before I was diagnosed , I remember all of my teachers being confused , because they thought was a very nice kid , but was also constantly in trouble .