I'm pretty sure I had (have?) a mild case of Covid for 12-14 days or so. During the first week of symptoms I had wild dreams, which I remembered all of. I've taken no medication (that includes things like Robitussin, Nyquil).
I might remember one dream per month on average. It's not common for me. With this, I remembered dreams almost every night. And they were surreal, vivid, very strange.
I think it's because the body is reacting to an unusual infection. So called fever dreams from an infection are a normal thing. A high fever would explain it, however I never developed a high fever. There was a change in my sleep pattern, as for 4-5 of those days I slept for extended periods of time due to exhaustion (over two bad symptom days, I slept for 12 hours per day; normal is seven hours for me).
My symptoms were sore throat, mild fever, general sick feeling, some abnormal pressure in my chest, light congestion. I only had a light cough for two days. This all went on for two weeks, with gyrations in the severity (one day I'd feel ~80% normal, then stronger symptoms would return the next day; on and on it went; two of the days I felt sick enough to nearly go to the hospital (I decided to test only if my fever got to a certain line; now I might do a blood test after the fact)).
To put it into context, I haven't had a sore throat in six years; maybe one sore throat in a decade. I haven't had the flu in nearly 20 years. I get about one mild cold per year, which lasts a few days. I haven't been sick longer than roughly five or six days in my lifetime. Odds are it was the SARS-CoV-2 virus (I also had a prominent source exposure, a healthcare worker I know that has been xray'ing Covid patients).
The dreams have disappeared now and I mostly feel better. My dreaming pattern is back to not remembering anything.