So I'm an 'ignorance is bliss' kind of person when it comes to labour - didn't do a birth plan last time, don't plan to this time, and just trust my OB and DH.

HOWEVER, I have never been told NOT to write a birth plan, and if a midwife ever told me she'd be offended by me doing something that is my absolute right, I'd tell her to get over herself and shove a detailed plan in her face!!

How rude!! It's your birth, your child, your life - you do whatever makes you feel comfortable and whatever eases the process for you. I'm hoping she worded it incorrectly and meant to say to try and be open minded especially since it's your first, but it doesn't sound like it.