Im old enough to know that a longer life isn't always a better one. In the end, you just get tired. Tired of the struggle. Tired of losing everyone that matters to you. Tired of watching everything turn to dust. OMG this quote.
But remember the Doctor's face in this scene. He is not overjoyed at the reunion. He is shocked at what his companions have become. Martha Jones, willing to destroy her race to save the Universe, just like the Doctor. And Rose Tyler, cheering it on.