system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Can we strengthen our immune system like our muscles? If so, is there a limit to how strong our immune system can get?
gpt
We can and do strengten our immune system. We do this simply by getting ill, when we do our body creates the antibodies to fight that illness and then it store the "memory" of how to make them so next time we get that illness we can fight it off quicker and easier. (this doesn't work for flu because the flu virus is always changing so every winter it needs different antibodies)