My health is too complicated to sum up as sick or not sick. I have chronic autoimmune issues, blood sugar issues, being too thin, and mental health related sicknesses; I have been told many times my mental sickness symptoms are apart of conversion disorder (speech issues, tremors that seem external -- I'm convinced I feel low grade earthquakes, my coordination drops off occassionally, ... and other things I'm not comfortable typing).
However, I rarely have colds and I've never had the flu as an adult. This could be because I limit my contact with people -- but I had been in college for 8 years and only got a bad cold once in all that time. It did take over 3 weeks to get fully well, but this may be normal? I'm unsure how long it should take to get over a bad cold. I also have several fungal issues (because of the autoimmune issues), so that might out compete for any other bacteria or virus that may enter my system.