I think the historic performance figures of the US stock market related to the unusually positive world position of the country after the last world war.
There was a baby boom, there was a space race, there was a 'cold war' and lots of planned spending and many tech advances.
I've seen an unending series of bubbles (and suspect they were happening even when I was a kid); the baby boomers looking for places to invest for a quick return, only to have their nest eggs smashed by the greedy sales people who (I at least hope) believed those were actually sound investments even though they should have known better.
Thus, I see the stock market as almost a casino; with odds rigged for the rich with not-quite insider trading.
My 'retirement plan' is to keep working, and to keep working, and to maybe live long enough that real socialism can happen after automation eats every job I don't want.