I think it's nearly impossible for many of us to read that essay and not think back to "what was I doing in March 2005 and what would have been different if I'd heard about and pulled the trigger to join that first batch?"
If I am feeling down about not joining YC 15 years back, and someone says 'why don't you feel bad about not buying bitcoin 5 years back, or GOOG 20 years back, or AAPL 40 years back, or X Y years back', I'll soon realize a pattern that I can feel sad about ANYTHING if I put my mind to it
And since it's our natural state to feel happy, and not feel sad, above knowledge might stop me from acting 'human' (depressed) over inevitable/infinite things.