For a single person, you don’t need much to live humbly in Singapore assuming your hdb flat is paid up

Food $20 per day or $600 pm
Utilities, mobile and wifi $200 pm
Transport $100 pm
Miscellaneous $100 pm
Total $1000 pm

You don’t need millions to retire unless you’re eating at restaurants for every meal everyday. If you do this, you will die early. lol