RAW wrote in one or another of his books that weirdo genius extraordinaire Buckminster Fuller used to perform the following exercise to limber up his mind. He’d go out to a hill just before “sunset,” and watching the sky repeat to himself “The sun is not setting; the earth is rotating on its axis.” After a while, it produces a somewhat vertiginous shift in perspective.
A variant I like, though I don’t really have the discipline to maintain it for any length of time, is to try and be conscious of the fact that you’re not acting “in the world” unmediated. You’re experiencing an incredibly complex, constructed virtual reality — an interpretation of electrical signals from different sense organs assembled by your brain. You send “walk” signals to your legs. Somewhere, in a sensorily inaccessible “real world,” leg molecules presumably move. Your brain coordinates visual and tactile input to confirm that you’re “walking.” You’re not looking at your computer screen; you’re looking at a movie of a computer screen cut, edited, and produced by the visual cortex sitting at the tail end of your squishy grey self-machine. Sounds a bit flaky, but it’s actually pretty interesting if you can keep it up for a while.