I just do US stock index investing. There has never been a 25 year period where the US stock market did worse than 3% if you include dividends. Let me know if you want sources. This year alone it is up over 10%. That being said there will definitely be down years but that is ok with me as they will even out over the length of my career.
Just be aware that saying used to be 10 year period, until it broke. It hasn't worked in the last decade or so, therefore roughly speaking durations keep expanding to reach the eighties. I suspect in 2030 the phrase will be something like ... never been a 50 year period ...
The part that worries me is hearing about all those boomers having to cash in equities and real estate over the next couple decades to pay off the medical sector... Who, exactly, is supposed to step up and buy that stuff at current prices / PE ratios? AKA where's the demand?
