If you look at my "unsolicited advice" post, I addressed exactly that issue. The first reaction people have to Dick's ideas is, "oh, this guy is trying to convince me that nothing can be known for sure and that's a very dangerous line of thinking, even though it's true".
But that's not what he's saying. I can tell you, if you want to follow the "nothing is real so everything is game", there are thousands of websites on the net. You can learn about ghosts, spiritual channelings, brotherhoods of light, astral travel, anything you can conceive of. Are those things true? Who cares if truth cannot be known anyway, right? Wrong!
It's not true that nothing is totally reliable. There are some things that are absolutely true, many things in fact. It's only because we don't understand how those things came to be true that we don't trust them and feel afraid of questioning them. "Don't open that can of worms". Dick has opened the can of worms, and in my understanding what he found shouldn't upset anyone, it makes perfect sense and, come to think of it, there's no way it could possibly be different.
Don't just have blind faith in your knowledge, question it, be skeptical, reevalutat it, then you'll have a safer ground on which to rest it. Until you do that you will not understand how the idea that nothing can be known for sure can be compatible with your gut feeling that you know a lot of things for sure. It so happens that it's possible to lay a logical proof of what you know for sure, only what you know might not be exactly what you think it was.
There's a name for discovering that what we thought was true is still true but in a different way. It's called progress. You sure don't object to that idea, do you?