What is existence?

WHAT IS EXISTENCE ?
Light, as we know it, consists of wave-like behavior as well as particle-like behavior which only belong to our interactions with it. Light doesn’t have any properties whatsoever of its own: without us, it simply does not exist.This is hard for us to wrap our finite minds around. But let me reiterate: without us, light does not exist. Now I hope you’re sitting down for this one – without light, WE don’t exist!! In short, our precious world (I’m being facetious) – without us – doesn’t exist!
Robin Starbuck