Had a fascinating experience the other day. I witnessed 3 acquaintances at it (LittleOneupmanship) until one of their childen had (supposedly) started crawling at 3 months, and another had (supossedly) been cruising by 5 months!
This started out after polite (?) enquiries regarding how DD2 is 'getting on'.
She's getting on fine thanks , progressing normally, TG!