That March had been an eventful month for Dick. The apparently mundane arrival of a delivery woman whose necklace bore a Christian fish symbol had triggered a cascade of bizarre impressions. He thought his unplugged radio was insulting him, his cat was trying to tell him something of vital significance, and that the KGB were sending him post-hypnotic triggers in the mail.
Well, we've all had days like that.
But speculative fiction writer Philip K. Dick seems to have spent most of his life in this condition. It explains his obsession with drug-induced alternative realities in works such as A scanner darkly, Do androids dream of electric sheep (the short story that gave rise to Blade runner) and We can remember it for you wholesale (which became the dreadful Schwarzenegger vehicle Total recall).
Weird stories from a weird man. The Guardian's book section has an excellent article about him, his taste for pharmaceuticals and the continually changing perception of reality they granted him.