title: clarification of Ember's this.get() method
body: <p>This is more of a general question than anything specific, but I'm new to ember and don't really understand when and how to use Ember's this.get('foo') (and similarly bar.get('foo')).</p>
  
  <p>For example, in my route I have a user object on which there is a property called credits</p>
  
  <pre><code>user = this.store.find('user', userId)
  console.log(user)
  credits = user.get('credits')
  console.log(credits)
  </code></pre>
  
  <p>my console.log shows me that user.content._data.credits has a value and also has a methods called get content and - more specifically - get credits. However, console.logging credits always returns undefined.</p>
  
  <p>if i set the user as a model though, using this.get('user.credits') in my controller works fine.</p>
  
  <p>I've read the docs about the advantages .get offers with computed properties, but could anyone concisely explain some ground rules of when to use this.get('foo') vs. bar.get('foo') and why it works in some places but not others.</p>
  
  <p>Thanks!</p>