The trope when person A is going through a loss of some kind and grieving, and person B tries to comfort them and empathise with A by saying “I know how you feel” and A just loses it and says something like “how could someone like you ever understand the pain I’m feeling” and B just takes it and apologises.
Then later A finds out that B has suffered through some of the most horrifically traumatising things you could imagine and A just feels like the biggest arsehole in the world.
Bonus points if A tries to apologise and B just brushes it off and acts like it doesn’t matter because ‘A was going through a hard time’ and A is just bashing their head against a wall because they want B to put themself first and get angry for once.