Question

Why do you think monthly expenses are less during retirement age than in younger years?

Answer 1

First, this isn't necessarily true, but generally the maintenance of stuff is cheaper than the acquisition of stuff.
If you need to buy a house, a car, clothes, etc - you're spending a lot of money and you need to spend it because you don't have anything.
If you already own a house, a car, clothes, etc there's no need to rush out and buy more. If you have planned well, by the time you retire you will no longer have a mortgage or car loan or student loan debt, etc that younger people still manage each month. Retirees typically are supporting only themselves and maybe a spouse, not their children (and usually not their parents). Fewer mouths to feed means fewer expenses. Finally, younger people save for retirement each month, retirees don't.

Answer 2

Thank you :D