The flu can also make you miserable for weeks. Not sure why you'd miss it.

I had the delta variant a few months back and it was so mild, I first thought it was just allergies. 2nd day, got a little bit of a tingly nose, stuffy, couldn't quite smell, but could still taste fine. 3rd day, same symptoms, 4th day, I was almost better completely. Fast forward about 1.5 months after I had that Delta coronavirus variant, and I got bronchitis from my young daughter. My ears became stuffed up for weeks, I had a bad cough for nearly 20 days before it was out of my system. The Delta variant was nothing to me. Here's more of that "anecdata."