Clara sinks down into the water up to her chin and closes her eyes.

"It's sometimes hard to guess because we spent a lot of that time on different planets, in different times." Opening her eyes, she smiles just a little sadly.

"Perils of being a time traveler. Can't ever keep anything straight." When she's gone from Earth long enough—how long was she on Tenzelore with him, and then in the TARDIS floating in the time vortex?—she loses track.

"But enough. Enough that it hurts."