How Do We Know We Aren’t Dreaming?

It’s a question that has baffled philosophers for ages: How do we actually know we aren’t dreaming right now?

Ted-Ed tosses out a few guesses, from the usual “pinch yourself and if it hurts, you’re awake” to more complicated theories that aim to prove the difference between fantasy and reality. Some say the proof is easy because, in the depth of dreamland, we don’t understand that the experience is not real. However, in a lucid dream, we are aware in real-time that we’re really asleep.