Have you ever had brainfreeze?
Just had a random thought that maybe there's a connection between cluster headache sufferers and people who never experience "brain freeze". I've had clusters for years and can fairly confidentially say I've never had brain freeze. When people talk about it after having a slushie or something I have no idea what that feels like.
https://www.vice.com/en/article/why-dont-some-people-get-brain-freeze/