The Christmas Special was packed with excellent one-liners - genuinely witty and performed to comedic perfection by Matt Smith. It was the "don't make my mistakes" one to Adult Karzan which cracked me up - a brilliantly self-depricating nod to Eleven's entire ineptness in matters of romance.
I think it was almost a reference to the way the first seven incarnations were portrayed as being completely asexual. Of course, the only other place we've had the Doctor musing on the origins on the sonic screwdriver is in another Moffat script...
Comments
i missed that one, like it!:D
"Doctor!"
"Merry Christmas!"
"Doctor!"
"Merry Christmas!"
"...Kazran?"