title: $watch is triggered directly after init, why?
body: <p>Why does <a href="https://docs.angularjs.org/api/ng/type/$rootScope.Scope#$watch" rel="noreferrer">$watch</a> trigger directly after page load and how can I prevent this?</p>
  
  <p><a href="http://jsfiddle.net/dcSRu/2/" rel="noreferrer">http://jsfiddle.net/dcSRu/2/</a></p>
  
  <pre><code>function MyCtrl($scope) {
      // Init scope vars
      $scope.data_copy = {};
  
      // If data_copy changes...
      $scope.$watch("data_copy", function(newValue, oldValue) {
  
          alert("$watch triggered!");
  
      }, true);
  }
  </code></pre>