You can retire the other way around - since you need roughly $20 saved for every dollar you need in retirement, reducing expenses by a dollar is as good as saving $20.
You can retire the other way around - since you need roughly $20 saved for every dollar you need in retirement, reducing expenses by a dollar is as good as saving $20.
That presumes knowing in advance what the dollar can buy you.
Here's a reductio ad absurdum: a couple live alone on an isolated island, they have and raise one child, and when they reach 67 they stop working and expect their progeny to provide for them as they were provided for in childhood.
Two parents provided for three people, became three adults providing for three people, became one adult providing for three people.
And when that kid reaches 67 and also decides to stop working? Now nobody's around to provide for them, so nothing is provided.
(What will happen in the non-reductio case is much more complex and unpredictable, between the never-ending potential of nuclear wars, and the ongoing but never guaranteed promise of technological progress currently dangling AI and robotics before us like a laser pointer to a cat…)