This will finally challenge the intestinal fortitude of the FIRE crowd. Like I've said before and gotten scoffed at, until your net worth goes down by the amount equivalent to 20 years of annual burn, you have not been battle tested.
Where did you come up with "20 years of annual burn" as the test? I mean that as a serious question. Since the rule of thumb is 25x annual spending as a common FIRE target, that seems to imply that it takes an 80% drop (from 25x to 5x, or, say, $1,000,000 down to $200,000) in order to be a real test. Has anything remotely similar ever happened to U.S. markets? Or international markets for that matter?
Anyway, this (so far) is still quite a distance away from hitting any of my triggers, and I just FIREd about 11 months ago. Far from testing my intestinal fortitude, this is still well within the part of the plan where I ignore it and continue on as usual. With a further 20-25% drop from here I'll hit my first trigger, which is to cut some of my luxury spending.