Hi Tony,
I know how you feel, it is as you say, a bombshell. My mum was diagnosed when she was 53. as you say, it's just little things to start with. with my mum, her spatial awareness was badly effected, so things like driving and directions. such a hard thing to tell sopmeone that has been driving for 25 years that they're no longer fit too, but saftey issues become more important than the argument, so if you do have to do that a little further down the line, don't feel bad, it's for the best. time scale wise, my mum is divorced from my dad, so it was down to me and my siblings to be there for her. i moved back and cared for her. she's just turned 58, and she doesn't know my name, but she still know's she knows me if you get what i mean? it's so different for everyone, so just do all you can like walking and exercise, things that keep her mind as stimulated as possible, the longer you can keep her the way she is, the better, just be as positive as you can. what i would say is get time for yourself when it all starts to become abit stressful, i didn't, and i wish i had. this forum is great for talking to people, and really use your family and friends that understand, alzheimer's cafe's and meeting groups, and when the time comes, look into restbite care, as it will mean you can stay sane and with your partner as long as possible. keep smiling, and making each other laugh, it helps, all the best xxx