I always had this doubt. I decided to share it with you.

You know that this is RED.

But you differentiate the colors just by the knowledge given by your parents and teachers. Your mother told you pointing a color that it is RED. But no proof that both of you are seeing the same color. If it is scientifically proven that both of you have the same wavelength coming to your eyes, there is a possibility that your neurons may be responding differently.

So what you see is may not be the world seen by others.

This is only a basic case. You can extend this thinking to other levels and understand how fool we are to get biased under other person's views.

I am sure that you understood what I am trying to say.