R. Star wrote:
The biggest weakness of Real Life is... that's such an emotional and moving moment for the Doctor that defines his psyche and changes him forever.... so naturally it's never mentioned again.
I don't think it's someting that NEEDS to be specifically brought up again..."hey doc, how's that dead daughter of yours"
but it was maintained more in his behavior after that point. It was something that shaped his personality and outlook and that is what stayed wit him for the rest of the show