I believe what Slim Boy Fat is referring to is called "qualia".
https://en.wikipedia.org/wiki/Qualia
With qualia we see the difference between conceptual knowledge and experiential knowledge.
I like this explanation -
Qualia is the term to used describe actual subjective experience and sensation, as opposed to mere knowledge and information.
The concept is best described by Frank Jackson's color blind scientist thought experiment: A scientist knows everything there is to know about the color red from physics, optics and neuroscience, but is color blind, and so she doesn't know what it's actually like to see the color red. If we then somehow repaired her vision so that she can now see colors, and let her see the color red, she would learn something new about red that she didn't know before, despite all of her previous knowledge about the physics and biology involved. This additional knowledge she gains is the qualia of seeing red.