It's an interesting "few glasses of wine" discussion topic; one
  of the things I love about the Internet, it's like that great
  cocktail party (or beer keg or college pot smoking session -
  pick your social lubricant) discussion, but at any time and any
  place and without the puking or hallucinations... well,
  youtubepoop nonwithstanding :P I want to believe in Many Worlds
  or Copenhagen - either one would be quite nice.* But here's
  where I think an example of the sticky thing is: optical
  illusions. In particular, the diagonal line. As humans, we find
  quantizing the / into x + y particularly confounding; a2 + b2 =
  c2... or in an opposite direction, square root of 2 - a
  never-ending ax-cut into the number system itself that pushes
  fractions deeper and deeper into the abyss with no end in sight.
  Or Pi - the attempt to cut a circle and turn it into a line and
  coming up with this number that makes us go "woah". And I
  believe it is a fundamental limitation of human perception that
  extends and becomes deeply embedded into our way of thinking in
  so many ways. Why do I mention optical illusions?* Look how
  easily our visual system is confused by the wireframe 3D box.*
  It's just a hexagon with lines through it; and yet it appears to
  jump out and push back simultaneously; our visual system can't
  process it.* No matter how we retrain ourselves, for at least a
  brief moment, it works. We are mystified by examples of purely 3
  dimensions.* Cantor's Sets leading to infinities of different
  kinds; running that diagonal - easily resolvable by flipping the
  set "up" into a 3rd dimension instead of a grid; the infinity is
  perfectly containable in a higher dimension. But we're mystified
  by it.* It goes someplace that seems improbable... because it's
  something we can't visualize with our mental systems entirely
  well... and this lack of ability based on our biological
  limitations extends into the very theories we use to describe
  the Universe. I'm not against many worlds, or wave-particle
  duality - or any stories that fuel the human imagination and
  take us to fantastic places - and systems that describe such
  fantastic places in detail; whether it be through literature or
  through mathematics... or art.. or music or movies. And I'm not
  discounting that numbers are practical; not at all; but I don't
  believe the Universe is mathematical; rather the system of
  mathematics describes the Universe very well; to a greater and
  greater degree of precision. But, to steal from a Buddhist
  concept (I'm not Buddhist but I like some of their stuff): do
  not mistake the finger that points to the moon for the moon
  itself. It's a tool; useful; practical; we're going to continue
  to make amazing things by it.* But I don't think its necessary
  to believe that numbers have an existence beyond the humans that
  use them, in order to continue doing what we do with numbers. I
  don't know if this makes any sense or if it's just babble :P