I can't remember the last time I had a cold or the flu. We haven't been sick at all since the pandemic started and for several years before then... no colds or flu either. I think for me it's due to a lot of things: I wash my hands more frequently, I wore masks everywhere for the 2 years the pandemic was raging (sI till wear one if an establishment requests or requires it), I get flu shots annually, I keep ALL recommended vaccinations up-to-date, and I am rarely in large social gatherings these days. I choose to spend more time at home. I am not a health nut and there are lots of things I could do better (but don't cause I'm lazy) but I think all those things have worked together to keep me cold and flu-free.