Because our entire universe is made up of consciousness, we never really experience the universe directly we just experience our consciousness of the universe, our perception of it, so right, our only universe is perception.
Ideas, unlike solid structures, do not perish. They remain immortal, immaterial and everywhere, like all Divine things. Ideas are a golden, savage landscape that we wander unaware, without a map. Be careful: in the last analysis, reality may be exactly what we think it is.