Absolutely true. The middle of the 20th century was the aberration, not today. Nevertheless, I think the point still stands: people from the (aberrant) era of stability are unaccustomed to instability.

Since memories only stretch back so far, and appear to be limited to generations, it's fair to say that Todd's generational (proximate) perspective was his "normal," and the "normal" for most people growing up over the last 50-odd years. This can still be true, even if that period was abnormal within the broader sweep of human history.

Furthermore, I'd argue that today's instability is something quite different from the historical mean. We're not simply regressing to the natural state of economics. We're moving out of an aberrant era of atypically shared prosperity, but at the same time, we're being rocked by the result of a decades-long experiment in supply-side economics that has confounded and further destabilized our position. What we were in then was not normal. What we're in now is not entirely normal, either. But your broader point is very true: there have always been wolves outside the gates. That we paid no attention to them for 50-something years is unusual.