How Can I?

Describing something when the speaker and listener cannot find common reference points to compare with is not easy. Consider the following:

How can I describe the colour of a rose to a person born blind?
How can I describe Beethoven's 5th symphony to a person born deaf?
How can I describe autism to a person born 'normal'?

If you know what the colour red is, I could describe the colour of a rose as "dark red", or compare it to an object with a known shade of red. However it is difficult for an aspie to describe autism to a neurotypical. Analogies are often made, but these never cover the entire picture, and even the 'part' which they describe depends on the experiences of the individual in question.