People over diagnose themselves so it seems more common than it is, but adhd is definitely real. Its not merely attention, its a set of traits like reduced working memory (and ability to utilize it) that manifest as difficulty in sustained attention / distraction. People who have it do a lot of other funny things than simply "get distracted easily", just ask the spouse of any person with add what _their_ coping strategies are and you'll get many humorous and perhaps unexpected stories.