The only thing running through The Doctor's head was the song he was hearing from the Oods. He couldn't help himself from feeling the strain of holding in the energy from the regeneration. He wanted his reward. But you never know how things could turn out. First he ended up saving Martha and Mickey, saved Sarah Jane Smiths son, saw Jack and helped him from his depression from the 456 having to sacrifice his own grandson to save the world. Oh The Doctor knows about sacrifice having to destroy Gallifrey losing his wife, kids, grandchildren, (we never know if The Doctor had more than just one grandchild) friends or whatever you can call friends on a planet that was threating to destroy the universe. (Back on track now sorry) In the end he got his final reward seeing his pink and yellow human, his Rose the first time she ever talked to him was his last. As The Doctor sets the coordinates on the TARDIS to hover over space safely for his regeneration now The Doctor starts to wonder what the next him will be will he finally be ginger doubt it. Oh no it's starting the tenths final words "I don't want to go" he starts to regenerate the pain of all his cells changing. The only words heard through the TARDIS is "Geronimo"