I don't know if I can be of any help on this. Here's a couple of thoughts though;
Love your surgeon! Listen to him, I say.
Take the other's with a grain of salt. The boss & even the C. They're only human & going with their own experiences & info that's been provided.
Sometimes people say things that, if we go with it, take us away from our purpose. That's why the book says the goals are so important, I guess.
Yes, your W is prolly hardwired to a certain personality. And that's also why Michele says to change you & not try to change them.
It's when you change, that the dynamic's of the R change.
I agree w/ the "your W may be less than effusive naturally" take, not the you may not be meant to be in a M. Read Michele's section of choosing a C. I don't know what could be done to change that now however, maybe other's have idea's?
Maybe he meant, you may not be meant to be in a M the way it is for you now? If that's the case, you're changing those behaviors anyway. I would talk to him about it more & see what he was trying to get at & whether he has solutions.
