Is It Really All About Perspective?

We often hear people saying "It's all about perspective", as if we are all equally ignorant, equally in the dark. While there's a grain of truth in this notion, I found it's not 100% true, because beside "perspective", there is are something called "dimension".

In this illustration two shadows on the walls are two dimensional shaped shadows (square and circle) resulted from viewing this cylinder from two 2-dimensional perspectives. The real "idea" of actually object - cylinder - needs to be seen from 3 dimensional view point, that is, not only looking at it from left and right, but also from "up" - a view point that breaks 2 dimensional surface.