oh, i totally agree. I think of great lines later...or else people dont actually quite give me an opening to say a line I have imagined!
I have had the question too... "so, when are you going to have kids then hey?" or the "you dont want to wait too long you know".... I actually replied once, with "actually I am going through IVF and have had miscarriages, so I hope I will have kids soon"...and the person went "oh sorry to hear that" and then walked away! I felt glad to have answered honestly though.

well, maybe I will start a new thread, with the things you'd love to say to people...