This is about what the 10th thought about before he regenerated. WARNING: SAD. Please review, your opinions are valued.
I do not own Doctor Who, it belongs to BBC.
He walked around the control room, throwing his jacket over a strut. This would be the last time these eyes ever saw the TARDIS. But the TARDIS would change too, wouldn't it? He'd be a new man in a new spaceship, complete with a new mind and new looks. He wouldn't be him anymore. Some other person would go walking off with his memories. This incarnation would die. He touched to controls absentmindedly. The TARDIS wouldn't really change. Her appearance would, but her personality was always the same. Stubborn, beautiful, smart, golden... And his thoughts turned to someone else who matched that description.
Rose.
His fantastic Rose.
She had really been his true love, though he scoffed at the idea of soul mates. They had been perfect.
Yes, she was alright. She had her mortal, aging Doctor. She was... happy.
And so he smiled slightly, small enough that you would have missed it if you'd blinked.
But would this new man love Rose? Would he cherish her memory the same way he did? Probably not. And that thought tipped the doctor over the edge. He had never said it. And now he never would. The metacrisis may have told her what he was going to say, but it just wasn't the same.
He snapped out of his thoughts when he realized he was glowing. His pain turned to panic.
"I don't wanna go," He said, and then the golden light engulfed him and burned him away into nothing.