Things can remain the same, while making a difference, fact versus truth?

Are you high? I'm high and I understand this completely. who DOESN'T know this? but can knowing really exist? does anything exist? YOU don't exist. YOU is just a word. YOU are ME, and we only exist as long as the other does. the stop sign is blue but it could also be red. and the sky is there above me but what if it were far away and under me and my feet were above?