Also, for much of that 1966-1982 bear market, buying stocks was largely unavailable to all but the already very wealthy, because to do so one needed a "stock broker" (and paying the required yearly fee or percentage of total assets to have one) and one paid a huge amount per each trade made (on the order of $50 per trade). So unless one had "family money" from an inheritance the average working Baby Boomer could not afford to get in on the bear market from 1966 through 1982 due to the costs of doing so.

Keep in mind that The Vanguard Group was not founded until 1975 (https://en.wikipedia.org/wiki/The_Vanguard_Group) and with them the first chance for Boomers to get in on what was, prior to that, the exclusive club of the very rich. And by 1975 slightly over half that bear market had already flown past.