Get the flu shot. The strains that were circulating in the Southern Hemisphere during their winter have already appeared here and it packs a wallop. Even if you never get the flu, keep in mind that some people can't get the flu shot (including newborns) and getting your flu shot also protects them. And not having gotten the flu despite not having gotten flu shots in the past isn't a good reason any more than not having getting snow tires because you've never had an accident is.
https://globalnews.ca/news/3782452/heres-why-canada-may-be-in-for-a-miserable-2017-18-flu-season/
https://www.canada.ca/en/public-health/services/diseases/flu-influenza/influenza-surveillance/weekly-influenza-reports.html
I think I already had the bug, at the end of September, which took me over 4 weeks to get over it. Then Darlene got the bug, at my 4 week mark and she took as long or longer to get over it.
Ouch, Bill! I guess you really are an early adopter!