title: Laravel 5 flash message flashes again after navigating away and using back button
body: <p>In my controller im trying to redirect back with a Flash message in laravel 5. This all works great. The problem is no matter how i set it up the flash message always re-appears if i navigate away and then come back by using the browsers 'back button'.</p>
  
  <p>So i have a users list with a delete button next to each user. When i click the delete button it calls my controller method to destroy. I made a little conditional in there that redirects back with an error if i am trying to delete an owner. I tried the following different ways to redirect back but with all i wind up with the same problem that the message shows again after navigating away and coming back via the browsers 'back button'. </p>
  
  <p>1 </p>
  
  <pre><code>return Redirect::route('users')-&gt;with('error_message', 'Some error msg');
  </code></pre>
  
  <p>2</p>
  
  <pre><code>Session::flash('error_message', 'Some error msg');
  return Redirect::to('users'); 
  </code></pre>
  
  <p>In my view i pick it up like this:</p>
  
  <pre><code>@if (Session::has('error_message'))
       {{ Session::get('error_message') }}
  @endif
  </code></pre>
  
  <p>So that works good, i get the message. But as soon as for example i click a user in my user list to go to the details page and press the browser 'back button', the message flashes again. I dont get why it keeps flashing that data, i was under the impression that it just flashes one time. </p>
  
  <p>Even if i try to clear it right after displaying (like below), it doesnt matter, it will always re-appear?</p>
  
  <pre><code>{!! Session::forget('error_message') !!}
  </code></pre>