Yves Klein was by far an original and an excentric. Surely an odd individual, he not only invented his own shade of blue (International Klein Blue he called it) and even dabbled in the field of classical music. He wrote several symphonies comprising one single note which was repeated for about 20 minutes. And his finest hour was when he tried to convince others that he could fly. Literally. Not a metaphor for anything.
William Blake had his first and only solo exbition in 1809, above his brother's drapery shop in Golden Square, Soho. He didn't sell any of the works. Almost nobody came. It was a flop, nothing more. But among the few which came was one Robert Hunt, who also wrote the only review of the show and published it in The Examiner. But the review was a fierce and destructive attack, which went so far as to call William Blake "an unfortunate lunatic" which of course couldn't draw.
Maybe Picasso seemed to be a polite and calm individual, yet you didn't want to get on his bad side. If you pushed him way too far he might get angry, and simply... pull a gun on you. Yes, it was loaded with blanks, but still you have to imagine Picasso as a gunslinger.
There is a "secret room" on the highest level of the famous Eiffel Tower. It is not a real mistery or something that has been kept away from the eyes of the general public, more of a little known fact. This room is the very apartment of Gustave Eiffel, the controversial and highly original creator of the monument which has become the symbol of Paris and by extension of France. Yet in his time there were many protests about the project and it was very close to be abandoned. The small apartment was reserved for Eiffel and his few, honored guests - among whom was Thomas Edison, for example - and only in recent times has been opened to the general public.
Vincent van Gogh made his first work when he was 27, and in about a decade he finished over 900 paintings.