Leonardo Da Vinci's personality is as enigmatic as his Mona Lisa. He was an educator devoted to informing the people of his time and to preserving knowledge for the people of the future. He became secretive, writing his journals and creative and inventive notes in a laborious backwards script decipherable only with a mirror. He had electric intellectual energy, beginning several wonderful creative projects simultaneously and working each to perfection. He left more than half of what he started unfinished. That which he did finished breathed with life. His technique which was to build layer upon layer from the skeleton upward required many days and weeks of sittings and created layers of minute variations that seem to live. (I find such pieces of his work reminiscent to the results of a daguerreotype, which took about 20 minutes to complete, the subject--man woman or child--being required to hold still the whole time; but of course no subject can hold perfectly still and each image records the variations of "stillness" that passes over those 20 minutes.)
Leonardo Da Vinci was meticulous and produced excellently wrought work. He left partially finished or completed works where ever in Europe he happened to be while working on it, whether Milan or Paris. He earned his living by painting works that he was commissioned to create. He carried the commissioned portrait the Mona Lisa with him wherever he went and refused to give it to the person who commissioned it. He could do something as insignificant as the drawing of a hand and as magnificent as the Lord's Supper. No one understands contradictory and complex personality yet. What is understood is that he was the world's most illustrious universal genius.