When it hit the lungs causing pneumonia there must have been some bad bacteria. The heavy duty antibiotics did allow me to make it. I know the flu was a virus but somehow the antibiotics hit the bugs in the lungs I guess.
Years ago, my favorite doctor explained what was recurring with me: first I would get a virus, which would weaken the immune system, making it vulnerable to a secondary bacterial infection, which would develop. So in effect, some people have both at the same time, and need those strong anti-biotics.