I must admit I have noticed that there seem to be more younger wives caring for older husbands on TP, but I have put it down to the fact that there are probably less 'older' ladies who would have access to TP .... (My husband is 20 years older, but it never mattered a jot until his personality changed due to AD!)
As for having a choice - we do and we don't: we may well have the freedom to do as we like, but if you've been married for many years and have inevitably shared all sorts of ups and downs, could you really just walk out because AD has messed it all up? Yes, it seems to turn our loved ones into strangers, and it wreckes everything we ever dreamt of, but what if the boot was on the other foot? Are we not still better off being carers than our loves ones who are truly trapped?
What we do need is lots of support, the odd opportunity to escape, and frequent chances to rant, rave, shout, scream, and ask lots and lots of questions - that's why TP is such a blessing! United we stand.