When you taste a cup of coffee, now what is happening is neurons are firing in your brain. But if you deny my experience, you're denying the conscious experience of everybody. You're denying life itself. In fact, the universe goes dark if you say that. And there are people who actually deny that. I might be one of those zombies.
Swami Sarvapriyananda teaches one of the shortest and most profound upanishads accompanied by Gaudapada's Karika. This lecture covers Mantra 7 (Part 2).