Problems retreiving session data on View page

Code:

$some_array = array(
  'first',
  'second'
);

//store the array as 'some_array' in session flashdata
$this->session->set_flashdata('some_array', $some_array);

another page:

Code:

//retrieve the array by it's key
$retrieved = $this->session->flashdata('some_array');

//now it's your regular numerically indexed array
echo $retrieved[1]; //second