Ignoring AC's 'ASSHOLE' remark below, you were doing ok in paragraphs 1 & 2 ((statistically; it is possible for virii to be a greater threat to 30-y.o. men) . Hell, even paragraph 3 is mostly good. But the last dozen or so words swerved into the fallacy of it being safe or prudent to not get the shot.
Vaccination and flu shots are about protecting everyone, including coincidental spread, and including outlier events. GP is misconstruing good medicine into something absurd in the name of toughening his immune system.
GP, try rationalizing that you're being 'tougher' by getting immunized. Your body gets forced to generate the antibodies even if you never get infected. Beyond that, if you need to live your dream of making yourself strong, try eating food that hit the floor or is past it's sell-by date. Lick coins and the handlebars at the supermarket for all I care. But don't get contagious. That's not a strengthening thing at all.
Get the shot, regardless. Advocate it at work. Spread good science. Anything less is enabling the dumbass Jennymac's of the world.