I started wearing a mask in crowded public places in about 2020 (for some inexplicable reason). I never stopped. I wear one in the metro. On buses. In crowded shopping malls (or even crowded small shops).
I used to get several colds per years and maybe one thing that caused me a fever each year (usually a flu).
I haven't had a cold or flu or any kind of fever-inducing infection since ... oh ... call it 2020.