Just yesterday, I went through a bunch of videos on stacks and
  found all of them really crappy because while I get the 'gist'
  of a stack... if I can't visualize it entirely in my brain
  working while it's working on the computer, then for me, I don't
  'get it' yet. Images of decks of shuffling playing *keeps going
  through my mind when I think of stacks, and that can't be the
  right mental analogy yet I haven't found a better one. *[the
  stack of plates is lacking] For something so critical to the
  workings of computers, I'm amazed that nobody made a decent
  animation of stacks-in-process... visualizations of stacks being
  corrupted, overflowing, and all the things that happen to
  stacks.