I wish I could say that I understand where you are coming from but then I would be lying...at least a little. My boyfriend does not know what I go through on a daily basis with this condition...no way he could not having this condition...but he has been SO good to me since I got hurt.
He DID go through a 2 year rehab with his ankle when he was in college so he could definitely understand my frustrations with the immobility and the long term rehab with physical therapy and the struggle to regain function. It's the constant, never ending pain that he cannot even begin to understand. But then...I hope he never has to. I wouldn't wish this on the people I hate most in this world...it's just too horrible.
And sometimes I get SO angry with my boyfriend because it seems like he just doesn't care...but it's not that he doesn't care. He does all these little things without me ever having asked, has taken over the grocery shopping because I can't push the frigging cart, is understanding about limits when it comes to physical intimacy, etc. What he does for me is so much more priceless though...he treats me like I'm normal. Day to day interactions are not about my pain...they're just normal. His support when I need it, his annoying pushing when I couldn't push myself, and his treating me normal are all things that...well...I can't really put into words what they mean to me.
I wish you the best of luck with your partner. It's those relationships that can make it or break it when it comes to dealing with this awful condition.