When I took the vaccine I was sick for a few days. I don't have any risk factors. I have multiple double vaxxed and non-vaxxed family members for whom covid was a minor cold and none for whom it was serious. I assume that as I am genetically closest to my family members they are a good predictor for how I will fare, if I haven't already had it without knowing it.

Why would I sicken myself for a few days with the next vaccine shot to marginally decrease the odds I will be sick for a few days from covid?