Your post totally made sense
the saving thing for me is that since I voiced my fears with dh (he's one of two brothers) he has made an amazing effort with his mum - he said it made him realise that he really didn't spend much time with her but not for any reason than it just didn't occur to him and she never said anything, they are quite close but not as close as me and my mum.
My brother is living at home with my parents at the moment, spends loads of time with them both and they share quite a few interests together - he'll even go shopping with my mum but he's not a great talker, my mum is always saying how she has no idea how he's doing, and worries about him constantly.... maybe its just character...
I guess I just worry about that distance from my boys, I think a lot of it is that I read 'raising boys' recently and it said from 0-5yrs moms are the most important role model and influence and then from 6yrs this transfers to dads and male role models - I guess that statement made me feel really redundant as they grow up and a feeling I need to get into their world as they won't be interested in mine, therefore, isolated - its rubbish I even hate the idea I'll have to go into changing rooms on my own when they are older, silly isn't it