Hey Harker, we must have posted almost at the same time last night!
I've just spent hours thinking about your post. I had the same issue with my mother as you had with your parents, only it manifested itself if different ways.
The first thing she said to me when I told her about my diagnosis was 'well I think your father handled it particularly well'. He had died from cancer about 2 months earlier and he'd kept to himself about it, I didn't know how serious it was until about a day before he died (and she didn't really know until then either).
I was completely open with everyone about my issues from the start and she must have seen this as a sign of weakness in me. I think that deep down she thought that dad deserved some sort of reconitition for what he'd been through and that I could provide that by being a complete mess over having the same thing.
I couldn't have a conversation with her about anything without some kind of reference or comparison to him being brought up. She was quite offended when I refused to use his slippers and dressing gown during my first hospital stay (which involved a fairly large and risky operation).
The gravity of the situation must have hit her about a month after I was diagnosed and had just finished my first round of chemo. I'm not sure what did it, perhaps coming to visit me in the oncology ward for the first time, which was as I was getting ready to leave after spending 10 days there (I'll never forget walking under the big 'Oncology' sign for the first time with an overnight bag). But at that point she decided to take 3 months off work and come and live with us.
I spent a lot of time with her during chemo and really, it was completely for her benefit. She still talked non-stop about my dad, but also started telling me about every single death story she'd ever heard of ('so and so' (a 90 year old friend of my grandparents) died, 'did your hear that Sir Edumnd Hillary died' (I'll never forget that one) etc.). She also told me about all the symathetic conversations people were having with her (people that weren't talking to me). I think she'd resigned herself to the fact that I wasn't going to make it, even though everything (bloods, scans, oconogists opinions) was overwhelmingly positive. She was building herself up for the next stage of her personal tradegy and had no-one to talk to but me.
To me she was clearly mentally ill at the time and needed help dealing with what had happened with my dad. But all her friends and the rest of our family (including my brother) wouldn't deal with her, and she refuse professional help, so she came to me (and I let her). When I look back now I can almost laugh at the irony of her building herself up for my death, not only infont of me, but exclusively to me.
She now tells me she didn't handle things well when I was sick. I tell her it doesn't matter and it doesn't. Its over now and I can't change it, but more importantly I've realised I can't change her and I can't fix her problems.
Like you, I've now feel like my life is the best its ever been. I'm healthier than ever and I can see more value in everyday things than I ever knew existed. I also know my own territory well enough now to know when lines are being crossed.
Thanks for your post Harker. Your a beautiful writer, keep it up!