Are you familiar with the concept of survivorship bias?
It's an important concept to remember when talking about the long term outcomes from adverse market events. "If they still have it today," for example, is a useful qualifier, because it subtly renders the statement almost tautological. "Sure, it was a bloodbath, but all the people who survived seem to be doing OK."
Yeah, don't go on margin is the lesson there. People that lost their hat on the housing crises borrowed too much (went too far on margin, which is what a home loan is). Anyone who just kept investing during any market crash in history is sitting well.
It's an important concept to remember when talking about the long term outcomes from adverse market events. "If they still have it today," for example, is a useful qualifier, because it subtly renders the statement almost tautological. "Sure, it was a bloodbath, but all the people who survived seem to be doing OK."