So it seems, it just happens to include everyone I've ever talked to about it

I experienced mild brain freeze as a child but it went away in adolescence. It doesn't seem pleasant so I don't envy those of you who get intense versions of it.

I have to be so careful eating cold things, it's like freeze++, brain glaciation.

I'm surprised it's so few! I'm in the 60-70% here -- I've never gotten it (despite many deliberate efforts), but I've never known anyone else who seems to be immune.