It's probably the weirdest thing I've ever read. Like, I have no idea what that book is supposed to be about.
Well. Dick was known for doing a lot of drugs, so that's not surprising, I'll have to check it out.
Most of his stories deal with people being unsure of what reality is, or what their identity is. The whole Blade Runner thing deals with Replicants being so close to being natural humans that one can't tell the difference.
One of his stories deals with a guy who accidentally discovers he is an android one day while getting ready for work, he finds an access panel on his chest and inside his chest there is a tape drive running. He figures out he can alter the universe as he knows it by editing and splicing the tape.
The story Total Recall is based on deals with the fact that the main character can't tell if his memories are real or not. (So, again, does Blade Runner; both Racheal and K have crises regarding memories that may or may not be real).
The odd thing about Blade Runner is that it is more like a Dick story than Dick's actual story. In that case, Ridley Scott beat him at his own game. The novel's Deckard is never uncertain that he is an actual human, and the book's androids never really get human enough to become totally sympathetic characters the way that Racheal does.