Incredibly, I've never had any of these illnesses. I see patients who have them all the time, but, I never have. Interestingly, I have never had a strept throat that I know of. I've been tested, but, never have had. There are days when it seems like every other kid in my office has it, but, I never got it.
Quite possibly, if I did immune titers, I might find that I've had subclinical infections, like I did with mumps. (Not for scarlet fever or impetigo, of course).