Marcus: 'Everything is what you judge it to be.' While the retort made to the Cynic philosopher Monimus is plain enough, plain too is the use of the saying, if one only take the gist of it, so far as it is true.
Me: We operate on the idea that what's true for us is true. It's the only way we can behave. But doing this may not serve us well if the way we see things is not how they really are.