baby boomers were in their highest earning period of their life and now they are all retiring and taking money out. For reference, the S&P 500 went from 45 to about 180 from 1955 through 1985. It closed today at 2108. That is why people like to talk about the last 30 years alot.

Also, a bug chunk of that move has come in the last 6 years where the market bottomed out at 666. That doesn't happen very often.