This advice is both common and crazy. Each individual does not live the average life. Being able to recognize once-in-a-lifetime events, and act on them, is a rational strategy, even if it seems like it is not the optimal strategy for the perfectly spherical portfolio belonging to a person with infinite lifetime.
I agree with this. I'd never touched my 401k until now, well, a few weeks ago. Anyone who couldn't see that this virus was a world-changing event wasn't paying attention. I did 'time' my way out of the market, but not so much back in. Even if I miss some gains, I just want things to stabilize some before going back in long.
I'm not sure it is possible to rationally recognize once-in-a-lifetime events, since by definition you've never seen them before and don't know how they'll play out.
