Philip K. Dick said this quote
“ What was on the other side?Donna said, He said there was another world on the other side. He could see it.He... never went through it?That’s why he kicked the shit out of everything in his apartment; he never thought of going through it, he just admired the doorway and then later he couldn’t see it at all and it was too late. It opened for him a few days and then it was closed and gone forever. ”