I've also found that I've gone from not being able to express what I want, to, in a certain extent, not 'wanting' anything much, so that I don't get too disappointed when I don't get.

I'm too selfish to put up with that :)

Around her 45th birthday my mum suddenly went "Screw you all, I'm sick of being self sacrificing" and starting to to call my family on their crap(*), and for the 5 or so years since then has just been constantly venting decades and decades of bitterness. Since she and I are very similar in a lot of ways I'm a little worried that might happen to me if I'm not careful.

That's how I justify it to myself anyway!

(*)Not me, I'm nice :) I say with a certain level of irony..