Flu? No, I never caught it either. Not a problem.
Until one year I
DID catch it. Then, Houston, we have a
BIG problem!
Projectile vomiting, explosive diarrhoea, inability to crawl to the bathroom before bouts of those two redecorated the house, feverish delirium alternating with prolonged bouts of violent shivering, a head that felt like somebody was trying to cut it in half with a rusty machete, and a body that felt like it was being set upon by drug-crazed muggers armed with baseball bats; That's what flu felt like.
It must have been a powerful reaction to the vaccine to feel like
THAT! A reaction to a vaccine is what the body does to respond to a very weak version of a virus. If the reaction is that strong to a weak agent, then I wouldn't fancy the reaction to the real thing!