I never wake up hungover, but when I do, it’s hell. Why?

After a night of drinking, I typically wake up feeling fine or even better than normal. I experience something called the “hangover effect”. It’s where the spike in glutamate after alcohol leaves your system causes you to feel clear and motivated instead of anxious or sick.

But every blue moon, I get a hangover that feels like my organ systems are failing. No in between.

Is it really just physiological chance or can you avoid this?