"Well, if you're a version of Jack, than I'd expect that you have rather a problem with dying, and so it could be rather a long time, though I expect I'd have more trouble if it were my Jack standing here, but she's not." The Doctor shrugged, sticking her hands in the back pockets of her her jeans, tilting her head. "So, really, how long ago, and what sort of adventures have you gotten up to?"