Why do people keep asking if we will have number 2. Number 1 is 18 months now

People will tend to have this mindset I guess? The shorter the age gap between siblings, the better and easier it will be for the mummy when both of them grows up together. One shot tired then sua liao. However, they tend to miss the part on how C.R.A.Z.I.E.R it can get. Hahaha Cheers Mummy!