so serious I don’t even know I have it yet!

I know you mean this to be facetious, but most diseases do work like this. Shit incubates, you feel mildly shitty for a bit, it spreads, then you either get better or you die. Ever notice how it takes a few days after encountering someone with the cold/flu before you develop symptoms yourself? Or how people with cancer never know they have cancer until they get themselves properly tested?