What constitutes a difficult day?

Most people would think that my difficult days are the ones where Ash is confused, irritable, forgetful and all those things which come with dementia but, although all of those things undeniably make our lives uncomfortable, the days I find most demanding are the ones where life is almost normal.  So 'almost normal' that I forget.  We laugh, have a joke, plan things, discuss what we're going to do and then, out of nowhere, he makes a chance remark or does some random thing and it all comes flooding back.  We had a lovely day yesterday.  Met up with friends, had a walk in the shade of a country park, lunch at a pub on the riverside and there was that 'almost normal' feeling.  Ash drove the hour and half each way with no difficulty whatsoever, I slept most of the way there and back - 'almost normal'.  He even remembered it and said several times during the evening what a nice day it had been.  So when we woke this morning, for a moment I thought that our life was back to normal.  That feeling lasted until he came back from collecting something from our local town.  He knew he'd collected it, knew he'd paid for it but didn't know what he'd done with it.  Cue stress, anxiety and all those other things that I listed at the beginning of this post.  All the things that 'almost normal' had made me forget and it felt we were right back at the beginning again.  Only we weren't of course.  The thing he'd collected was found, peace was restored and we took ourselves off to the village coffee morning where we sat and chatted to friends 'almost' like a normal couple.