Susan,
Was it the same bacteria all three times? Did you feel it was treated aggressively enough? Were you back to baseline in between the pneumonias? I'm sorry you've had a rough six months. Personally, I've had some years be better than others.
This year, I spent Oct to mid-May either a lot sick or a little sick, with a variety pack of bacteria and never getting back to my old version of well in between flare-ups...except now, I'm there -ish again, and crossing my fingers it lasts.
Has there been anything new in your life you could attribute to the bad spell? For example, the obvious, a new bacteria living in your lungs; but also renovations to your home/workplace, hormonal changes, an increase in stress, a neighbor who likes to use his fire pit all weekend...etc.