title: MongoDB Populate Aggregate Unwind
body: <p>I have the following data structure for my user model:</p>
  
  <pre><code>{
   _id: object,
   name: string,
   quotes: [ { quote: string, createdAt: date } ],
   friends: [ { _id: object } ] (this refers to the _id from the user model)
  }
  </code></pre>
  
  <p>What i'd like to do is return this:</p>
  
  <pre><code>{
    quote: string,
    createdAt: date,
    _id: object (friend's)
  }
  {
    quote: string,
    createdAt: date,
    _id: object (friend's)
  }
  ...
  </code></pre>
  
  <p>sorted by createdAt = recent to oldest</p>