Shower thought ... Maybe everything else is mutating, too?

My two roommates and I just finally got over some kind of weird cold-like illness, took us 11-12 days to recover. Not Covid (based on 1 negative PCR test for one of us; I'm assuming we all had the same thing). Presumably, just your random cold/flu-type bug. A remote co-worker (400 km away, both of us in EU) has been experiencing a similar illness for over a week now, still not over it.

It took the three of us almost 2 weeks to get over it. The symptoms kept changing every 1-2 days (sore throat, then harsh cough, then chest/lung pain, then gas and intestinal issues, then headache, then back to coughing); had a false "I'm all better now" moment halfway thru, then Phase 2 kicked in. On top of which, I don't get sick much, and when I do, it's usually very mild and I'm over it very quickly.

So, I have a hypothesis. Thanks to all of the social distancing, OCD hand-washing, masking, etc for the past 18 months, "regular" colds/flus/germs have probably been going through some pretty extreme evolutionary stresses, just like Covid ... and are probably mutating/evolving a lot, just like Covid. Except all the researchers and specialists are pretty much completely preoccupied with Covid research/work, so no one has been paying much attention to all the other day-to-day respiratory illnesses.

I've seen a fair bit of news about how colds/flus have been much less common of late, due to the Covid-precautionary measures, but I have not seen any research or discussion about how those measures might be impacting other non-Covid illnesses.

Thoughts?