shobhan responded to what is intuitive design?, and eventually introduced me to qualia.

https://en.wikipedia.org/wiki/Qualia

i liked daniel dennet’s description:

qualia was “an unfamiliar term for something that could not be more familiar to each of us: the ways things seem to us”.[9] He identifies four properties that are commonly ascribed to qualia.[9] According to these, qualia are:

ineffable: they cannot be communicated, or apprehended by any means other than direct experience.

intrinsic – they are non-relational properties, which do not change depending on the experience’s relation to other things.

private – all interpersonal comparisons of qualia are systematically impossible.

directly or immediately apprehensible by consciousness – to experience a quale is to know one experiences a quale, and to know all there is to know about that quale.

If qualia of this sort exist, then a normally sighted person who sees red would be unable to describe the experience of this perception in such a way that a listener who has never experienced color will be able to know everything there is to know about that experience.