I've been rewatching the 9th and 10 Doctor seasons on BBCAmerica lately and this came to me. I never realized how much I missed Rose Tyler until I started watching her two seasons again.
They're not mine, by the way. No way - no how. :)
He's known a lifetime of companions, known men and women and aliens from all over the universe. But he's never known anyone quite like Rose Tyler.
She is both wonderful and infuriating in her human innocence. Her eyes take in all that they can, wide with wonder as they gaze upon all of space and time. She asks questions; her thoughts constantly spill from her mouth as she attempts to gather answers and catalog all the things she learns.
He watches her grow as they travel the universe. He also watches her innocence fade, replaced by staunch wisdom and lines around her eyes. She smiles less after her experience with the TARDIS. He sees it with his new eyes, eyes that know her while she does not recognize them.
"I miss your old face," she tells him one morning over tea.
He does not tell her that he misses hers, as well.