When I play the piano, I will just start doodling and see where
  it comes. I like to play very fast and lots of arpeggios and
  sometimes I smash the lower keys with octaves; going to
  different keys and such. It's improvisational, although there
  are patterns, and I don't what the style is; never figured it
  out. Anyway, as the player, *I don't know* what's coming next as
  I'm playing; it just... comes. I always have my mind on the
  resolution as I play - not knowing what it is, but knowing that,
  at some point, the song will temporarily end. [but I can pick
  the 'theme' up again later, continuing the song after, say, 5
  years of pause, if I like) - but that temporary ending is in
  mind somewhere as I play, as I can stop the song anytime I want
  to. When I notice patterns I'm following, either of chords or
  style, I try to break the pattern, unless it's a pattern I don't
  particularly mind. Cause and Effect are a wonky, tricky thing to
  determine. They intermingle, because the ultimate effect (the
  end of the song), while unknown, is a known and it
  back-influences the present, while the past also affects what
  I'm playing. But Time isn't liinear. It skips around, goes
  backwards, inverts at least in the context of improvisation. As
  far as "reality" goes, I have no reason to believe that reality
  doesn't also work in the same fashion. If it works in this
  microcosm, no reason it couldn't work in a macrocosm, as it
  were, just not everywhere perhaps.