I got that a lot before we had DD. at that time I didn't know how to respond because I've never had a baby before. So I smiled and nodded and proceeded to ignore their future comments. If we have a 2nd one, I will most likely say 'I've done without it so why start now?'
I had friends of my mum laugh and say the whole "talk to me after the baby" thing when I mentioned I wanted a natural drug free birth with DD1. Admittedly, this was someone who had an epidural as soon as she was 4cm. I didn't smile and nod. I told people I know I can do it, many other women do and the human race would be wiped out if women couldn't give birth without drugs seeing as that's a relatively new thing to do. Two natural, drug free births later (one being a Homebirth) people don't say that much anymore lol.