Another "How do I hide the menu one only one page" post.

Hi. So sorry. I’ve been looking and trying and breaking my sanity all over this ridiculous question which seems like it should be so easy:

I just want to hide the menu on this one page:

http://siainedinburgh.co.uk/wp/you-must-be-over-18-to-enter/

But it seems there is no internet god looking out for me.

Everyone say, “Its so easy! Just take it out of your template, DUH!” and yet I don’t see anything referring to the menu/nav/menu ul or anything of the sort.

<?php
/*
Template Name: over18
*/
?>
<?php get_header(); ?>

<div class="container_16 clearfix">

  <div class="grid_10 alpha">
    <div id="contentwide">	  

	  <?php if ( have_posts() ) : ?>

        <?php while ( have_posts() ) : the_post(); ?>

          <?php get_template_part( 'content', 'page' ); ?>

        <?php endwhile; ?>

      <?php else : ?>

        <?php get_template_part( 'loop-error' ); ?>

      <?php endif; ?>

    </div> <!-- end #content -->
  </div> <!-- end .grid_10 -->

</div> <!-- end .container_16 -->

<?php get_footer(); ?>

So that’s my code in the template. Hoping I can use that to apply just to that one page and finally be done with it.

If there is a better way that does not include this code:
.page-id-71 #menu {display:none}, or whatever permutation, (which hasn’t seemed to work) I would welcome that.

I want sleep. Please.