"Songs my mother taught me"

Began to read Marlon Brando's autobiography: "Songs my mother taught me".
With the advent of Marlon Brando and James Dean, who were followers of Stanislavsky's system, into Hollywood, the way of acting was changed forever. Notwithstanding Brando is one of the biggest genius of screen acting, his wide personality can be easily apprehended even without seeing him during reading this book. Countless wicked story of his unusual life and range of wisdom thoughts.
I was quite amazed when read the same passage that I'd already read in autobiography of Johnny Cash. Both of them said that they can remember every song that they heard, especially the old ones. In addiction, at the moment when they were writing their autobiographies both of them remembered more that 1000 songs. I just can't imagine that. Of course I know more that 1000 songs, but I don't remember every song. I can't explain it, maybe in those times there were less garbage songs and it was pleasure to listen to them and remember because no one had such variety of music that we have.