gigolo or mistress can...

on a serious note, i believe when they say they can save 100% of their earning, it is their typical 9-6 day job. And they only live on the income from their investment. Thus thats how they can save 100% of their earnings aka salary.

Live with parent no need to give them monthly maintainence/ allowance-ah???

This is called 'pai kar chai' or 'ee sai chou' 

It is not the money but the act of giving  . This is part of chinese culture of Filial piety. It shows respect and gratitude to your parents.

Remember the CNY advertisement - scene at old folks home and elderly ladies boasting bout their children high income, each one progressively higher then the other except 1 meek lady keeping quite. Next scene a proton roll-in (non-high income child), it was the meek lady's son visitng her while all other ladies can only look on jealously.....  Filial piety my friend   

My mother & father in-law both gov servants, gets monthly pension with free health care and paid up house & cars but we still give them monthly allowance; do they need the money? No. Can they do with the extra? Yes. Do they use the extra? I dunno. It is just my duty to my parents