Remarks :
In short, lessons learned from this mega flood:

Govt should tell us in plain language where and when the floods have been expected to happen.
The info should not contradict one another.
Better water management is needed.
Those in the areas where the authority has decided to receive and to "keep" the flood water should be compensated.
These areas should be the thinly populated areas.
The people living there should be asked of their opinions first.
They should never be forced to sacrifice.

Etc....

Summary of the above in my own words:

Misconceptions of life amidst the floods

"With enough food one can live for months in the middle of the flood water."
-  The truth:
Without electricity or gas there is no way to cook.
Can you eat chips for weeks?  No TV, radio, newspaper.
Fridges, mobiles, and wi-fi do not work.
The air-conditioners and fans don't work:   it will be hot and suffocating!

"One can go upstairs if water reaches the ground floor."
-  The truth:
The flood water can be very dirty and smelly.
There are mosquitos, snakes, centipedes, dead rats and etc...
And what if the water rises to the second floor....

"Not in the risky zones.  Should be safe..."
-  The truth:
The world is changing fast.
Many places on earth are seeing unexpected large-scaled disasters.

Etc....