It's very much possible to represent all complex forms through a combination of primitives.

In fact, this is also how our brains are able to remember what a particular object is, even if we view it from a perspective that we've never seen it in before (it's believed that our brains make use of only about 30 primitive forms called geons to construct simplified forms of ALL the objects we see around us).

"Blocking out" your drawings with primitives is a technique that many pro's use to ensure that the perspective and proportions of their artwork is solid before they start adding details.