I see both sides...
I'm a very proud mum and like to boast about my baby's acheivments alot, BUT I think it's wrong if you then ask about someone elses, and imply that theirs isn't as advanced as yours...Thats just rude.
One thing which really upset me though, for example, was when I wrote on facebook "OMG! Rory is only 3 months old and he just rolled over!!! He's so clever!"
And then another mummy totally deflated my excitment and made me feel crap by writing,
"Yeh, thats when most babies start to roll..." as if it wasn't anything to be proud of. It made me really upset! TBH even if he was 8 months old and it was his first roll, i'd have been harping on about how proud I was. I thought that was kinda mean...I wasn't trying to say anything wrong about her baby, and I never say to others when they say that their baby just learnt to roll, "Well MY RORY rolled at 3 months!"