Imagine the two of us, arm in arm, looking at a sunset, where the horizon is fretted with golden fire and the deep blue night encroaches from the opposite side of the sky. “What beautiful colours”, I say, and you agree.
And then, in the space of the following silence, I am struck by a worry. I can point at the sky and say it is blue, and you will concur. But are you really seeing that blue the way I am seeing it? Perhaps you have just learnt to call what you see “blue”, but in actual experience you are seeing nothing like the vivid, rich, blue I see. You are an imposter, calling my blue by the same name as yours, but not really seeing it the way I do. Or, even worse, perhaps I am the one seeing a pale imitation blue, while yousee a blue that is infinitely richer and more splendid than mine.
Now I admit that this worry lies in the realm of philosophy, not neuroscience. You might even ask me why I am worrying about this when we could be enjoying the glorious sunset.
This consumed my imagination as a child. No one else understood.
Oh my gosh, my sister and I talked about this regularly!