I must be one of the 59 %. My health hasn’t been too good for several years and I spent a couple of days in the hospital some years back due to the flu which went into my lungs. Since then I’ve been taking the shots and have not had the flu in spite of exposure. My wife has done well too.
Without rendering an opinion as to the effectiveness of getting the flu shot, it’s very likely that your body’s natural immune response to actually getting the flu is the reason you haven’t gotten it again rather than the vaccine.
I’m like you. I get sick if I don’t get the shot, and usually stay well with it.