How did bill finger get the idea of Batman?

I met Bob Cane in Dec. of 1980 at the New York VA hospital. I had a long discuss with Bob Cane and He told me that he got the idea of his batman characters during his visits to mental institutions. The riddler was characterized from a mental patient who suffered from hyeanna disease a laughing disorder. the patient would just stand in front of a mirror and laugh all day as he look at him self in the mirror, the penguin was characterized from patients who were on the drug thorozine and developed what is called the side effect of the slow walk shuffle, Batman was a self portrait of the man himself ,Bob Cane, and once he had his core characters his formula for creating his characters was created.