nodejs process.argv gives different set of arguments each call

I am running nodejs on peppermint (did a curl and then a sudo install). I am trying to use the function process.argv, but every time I call it I get a different output. For example, here are two consecutive calls (a little more info, I'm trying to work through the examples on nodeschool.io):

First time:

[ '/usr/bin/nodejs',
  '/usr/lib/node_modules/learnyounode/program.js',
  '67',
  '22' ]

Second time:

[ '/usr/bin/nodejs',
  '/usr/lib/node_modules/learnyounode/program.js',
  '75',
  '78',
  '44',
  '32',
  '10',
  '26',
  '83',
  '48',
  '17' ]

Is something wrong with my node install?