What did he mean by this?

You can't tell a lie if you don't know what's true, because lying is knowingly saying something untrue. Since truth cannot actually be known, it's impossible to tell a lie, because you have no way of verifying the veracity of your statements either way.

>>1532520
lying isn't neccisarily telling something that's untrue, but telling something that you think is untrue. lying is about having the intention to deceive

>>1532500
I take it as him saying liers and manipulative people in general are usually more astute observers of society.

Gotta understand the system to game it.

>>1532500
It means that he who cannot lie does not know what the truth is.