system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Your immune system causes symptoms like fever, swelling, etc, when fighting an infection. I usually get more mild symptoms than my wife when we both get sick. Does this mean my immune system is weaker or stronger?

If your immune system is what causes those symptoms, does That mean my immune system can't fight as hard, or that it doesn't have to fight as hard to win.
gpt
That's an awesome question, but unfortunately it doesn't have a clear answer, as there are so many variables that can change the response.

There are 2 components to your immune system: the innate and adaptive. The innate just travels around and freaks out at everything it doesn't recognize. It doesn't matter if it's the common cold or anthrax. (slight exaggeration, since it does matter if it's bacterial or viral). It's going to react the same way. These are responsible for fever, phlegm, swelling, etc.  These happen within hours of being infected. The end goal here isn't to kill the infection. It's to fight until your adaptive cells can bring reinforcements.

You also have an adaptive immune system. These are (primarily) your T and B cells, which take time. They have to 'study' the infection, find a good way to kill it, and then mass produce the antibodies. This can take anywhere from hours (if you've already made antibodies) or days-weeks (if it's something brand new).

Let's say you get an infection that you've seen before. Your innate system attacks right away, and you start to notice those general signs of being sick. But then, your pre-formed antibodies quickly kill it. 

Or maybe it's a brand new infection, but for some reason, they don't trigger your innate system as strongly as hers. Therefore, you only get mild symptoms until your adaptive* system kills it. It's also possible that your innate response being smaller actually lets the infection grow, causing you to be sick for a longer period of time

At the end of the day, you can't really say your system is stronger or weaker. The real question is whether it's good enough, and it sounds like both of yours works.