Reality is it the same for all

I have had this in my mind for almost 10years now but I am writing because I read something on http://alternative-theory.blogspot.com/2006_01_01_archive.html which sounded very similar.

Do all human beings see the same thing or what we see form totally different images in the brain of one from one person to another.

Say I see a square box but some other person sees it as round but the way he describe it as a square bcoz it depends on the way our mind was conditioned from birth is. I know it sounds a bit weird but it is possible. Though there are other senses that might confirm it. It might not be true for the visual observation but for sound and smell it very much possible.

I think i should sleep.