Boulders, precariously perched
   on the edge of a precipice.

Do the residents
   of the huts
     down the mountain
   ever think of that boulder?

Maybe they thought not being 
   directly under it would keep
   them safe, but what bounce
   might a boulder take --
      freefalling, tumbling, hitting 
      outcrops, sliding on scree, 
      cracking to fragments,
      being not spherical in the least,
      and so on?

My guess is that they never think
    about it... or think about it
    every minute. 

And in some moment when
   they aren't thinking of it...
      SPLAT!