Hm, mrAru having been in the Navy, was given a flu shot evey year for the last 10 he was in, and got the flu every year. I got a flu shot in 92, and got the flu as well. Nothing like both of us down at the same time. Thank god for roommates. Last 3 years, no flu shot for him, and no flu. I will however get at least one bout of pneumonia a year, but I have COPD from phosgene exposure, and almost anything serious will end up making my body want to drown me.
I have never met anyone that has gotten the flu every year even without a flu shot. I think you are confusing the common cold with the flu.