The last time I 'caught' anything was that Russian flu, in 1977. It was rather nasty (high temp, weakness etc) but from all reports at the time you'd think it was going to be the Dreaded Lurgy. I didn't find it all that bad.
Haven't had anything since (not even a cold!) so I'm hoping my immune system is in good order. Being a teacher all my working life has probably given me a lot of antibodies, having been exposed to a myriad germs and bugs from my pupils.
At the end of the day (hate that expression!) we can't do more than wash our hands, eat sensibly and avoid large crowds if possible.
If I ever dared to look glum,my blooming father used to say, "Cheer up! It may never happen!" Good advice really...