system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why we don't build up immunity to seasonal allergies over time.

Not sure if "immunity" is the correct word in this case, but how come they affect us our whole lives?
gpt
Because allergies are an immune response.

Allergies are basically caused by your body overreacting to a perceived threat (like pollen or dust mites or whathaveyou). So you're being exposed to something that's actually quite harmless but your body presses the panic button anyway.

This happens largely because your immune system is *bored* and has nothing better to do, so it acts up like a kid who is bored and has noghing better to do. Studies on children suggest that kids who get sick a lot develop fewer allergies.

Now, exposure to small and regular dosages (amping up all the time) can erase an allergy, but this apprach wouldn't be effective against seasonal ones.