In a way, I'm glad that Corona lifted the awareness about post-infection issues. The common knowledge usually was "you're sick for a week and then you're fine".
I don't have ME/CFS, but my body started to react weird to some harmless common cold infections. My blood pressure drops and remains low, sometimes for weeks. Makes me feel dizzy, makes working out almost impossible.
Also, I had some stomach bug several years ago with some side effects lasting for 2 months. Most people don't believe that a "harmless" infection can cause side effects for weeks (and neither did I), but it's a thing.