Studies have shown that people develop their deep seeded feel, tolerances, hopes, cautions about the stock market from what occurred to them during their accumulation phase in life - and what is experienced in those years tends to stay with a person till they die (even if they start to see the opposite happening later in life). Looking back at some time periods... those in the 30-50 age range during the 90's tend to hold onto this gut feeling that a roaring return from stocks is inevitable, while those who endured the great depression at that time period in life carried the trauma of it through the rest of their lives... always feeling that the market wasn't to be trusted, despite it's return to it's historical trend upwards. Many think that the lackluster 2000-2015 period where we've seen practically no overall change in the market in total, yet a roller coaster at the same time of highs and lows, has created a generation entering their 40's and 50's that thinks of the market as gambling... the next generation (those in their 20's and 30's now who don't really understand how abysmal it's been the last decade and a half), will look at that previous generation as having a paranoia about he stock market that they likely won't understand as longer term trends push the market back to it's long term upward trend of 10% a year.
To answer the question... I think we would like to avoid getting stuck in our comforts (wisdom) that were built on a 10-20 year horizon, when the markets tend to follow a generational pattern that recycles every 30 years. In that, it helps to get a sense of how the people felt about the market 10 years before you got involved in it... because that's likely what you're going to experience just before you reach retirement