All4One, that's fine, but who pays for their pensions?
By the time you are sixty, if you have lived carefully, you will have paid off your mortgage and the kids will have left home. With those two millstones gone, and no rent, you should be able to cut back to two days a week work, even of manual labour.
Of course, you could always be like a couple I know in their late fifties who both have good jobs but find themselves with debts of $250k, living in rented accommodation. Or a mate who has just gone bankrupt at 48 because of his wife's spending habits. I have NO interest whatsoever in contributing to these peoples' pensions.