You have absolutely been sick, but your immune system fought it off. You have a permanent low level of opportunistic infections because everyone does.
You may not have had symptoms, but that's a very different thing.
And I assume you've been vaccinated against all the usuals.
Sorry, yes, I've had colds and a cough or two for sure. I don't think I've thrown up in 35 years though since I was a child.
When I meant sick, I meant like a longer sustained thing that needs treatment of some kind. I didn't mean I never stayed in bed watching the price is right for two days.