· Used 'mirror writing' so other would not steal his work and/or to hide his work from the Roman Catholic Church.
· Dug into graveyards at night to steal corpses and study human anatomy (and find out where the soul was).
· He was a humanitarian and therefore a vegetarian. Yet he made sketches of hundreds of war machines.
· He was a left-handed dyslexic and procrastinating perfectionist who left many paintings unfinished and destroyed most of his work.