system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come our bodies adapt so we only get the chicken pox once, but we always get the flu and other things?

Why can people's bodies adapt so we can only get the chicken pox once, but we can never adapt to the flu or the cold or other small sicknesses? [Answered]
gpt
It isn't our bodies. It is the illness. The cold and the flu are actually tons of different rapidly evolving viruses. You do actually become imune to a particular cold strain once you get it... but there are a few hundred more waiting to get you next. 

As to why the flu and cold viruses adapt faster than the chicken pox virus, i don't know.