But that's what I see, all the time. Doesn't it drive you mad?

My head, it's killing me.

I think you need a doctor.

With his kiss, the knowledge drained out of her. Everything that she saw, past, future, present, the pain and hardship and loss, the friendship and love, she lost it all. And with it, her memories of the Doctor. He knew as he drained the memories from her that she could never remember again, that the knowledge would kill her, as the power of the vortex would also kill him. Even if she couldn't remember, saving her life was worth it. He caught her as she fell forward, and gently supported her until she lay on the ground. When she woke up later, it would be without the knowledge of their travels together. She would wake up Rose Tyler, a London girl who works at a shop. Any memories of him or of their adventures together would bring the knowledge of the time vortex back to her brain, tearing her apart and eventually killing her. He could never let that happen. He would watch her though, as she grew old and married her Ricky and had her golden-haired children. He would keep her safe, keep her planet safe; he could give her that much, his Rose.