title: Is there a reason why extension methods can't be invoked directly on "this"?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/3906170/why-can-you-not-invoke-extension-methods-directly">Why can you not invoke extension methods directly?</a>  </p>
  </blockquote>
  
  
  
  <p>Lets assume the following code:</p>
  
  <pre><code> public static class MyExtensions
  {
      public static void SayHello(this Foo self)
      {}
  }
  
  public class Foo
  {
      this.SayHello(); //this works
      SayHello(); //this does not compile
  }
  </code></pre>
  
  <p>I'm just interested in the reasoning behind this, why can't extension methods be invoked on an implicit <code>this</code> ?</p>
  
  <p><code>this.SayHello()</code> and <code>SayHello</code> means the same thing when applied to instance methods.
  So why use different behavior when calling extension methods?</p>