ADHD
I don't have any structured thoughts (that I want to write down yet) on having ADD, but if you think you have it, go check out the ADHD subreddit and learn more. Just knowing that you have it is a life changer.
Later that day... I found the 'How to ADHD' youtube channel. Excellent.
edited: 2018-11-15 (fixed link to actual subreddit) 2018-11-16 (added channel screenshot to link) 2020-12-09 (Removed broken image link)