Bilbo Baggins has ADHD! It says in the first chapter of The Hobbit that he didn’t remember things well unless he wrote them down! – Absolutely! He also:
randomly bursts into song
is driven by his emotions and impulses
took like 70 years to write a book
his mind works in ways that other people don’t follow easily
talks too much and has no idea that his listeners aren’t into it because he’s so into it
h y p e r f i x a t i o n