https://en.wikipedia.org/wiki/Paintings_by_Adolf_Hitler

"In his 1925 autobiography Mein Kampf, Hitler described how, in his youth, he wanted to become a professional artist, but his dreams were ruined because he failed the entrance exam of the Academy of Fine Arts Vienna. Hitler was rejected twice by the institute, once in 1907 and again in 1908."

That is where the reference is from. Pretty deep.