Negotiating with a Five Year Old

While driving with Lorelei a while ago, I was trying to convince her of the benefits of the flu shot.  Our conversation went something like this... 
Lorelei: I don't want the flu shot...
Me: I know, but we need to get it, it will keep you healthy.  We don't want you to get sick and we don't want you to catch the flu and make us sick, or your friend (who has no immune system), or Ethan.
Lorelei: I don't like needles!
Me: I know, but we won't go back to that doctor.  I know it hurt when he gave you the flu shot last year.  We're going to Ethan's doctor, we'll all get it at the same time.  If it hurts too much with his doctor we'll go back to our family doctor the next time and continue to only go to her until she retires.
Lorelei: Retires?  What does retires mean?  (Way to change the subject.)
Me: Well, it is when someone is able to stop working because they're a certain age or have done their job for a long time.  (Hmmm...how do I explain this?!)  Pepere is retired.  He used to work for the army but now he doesn't.  He retired from that job.  Umm...I can't think of anyone else you know who's retired.
Lorelei: I think Omi should retire.
Me: Why is that?
Lorelei: So she can move to Canada and spend time with me.
Me: (Can't argue with that logic!) I'm sure she'll love to hear that!  Now don't forget we'll go as a family and you'll be okay.  Daddy or mommy can get the flu shot first if you want.
Lorelei: I do!  Daddy first, then mommy and then Ethan.  But I don't want it!
Me: I know, but you need it.  We all do....  (and here we go again through the whys of it all.)