A neurologist is quoted on an online forum as saying to someone who was impatient about the fact that it was taking her so long to obtain a diagnosis: 'no diagnosis is better than a wrong diagnosis'. So here we have a sensible neurologist - pretty remarkable.
But having thought a lot about our experience, I would go further. I would even say that, depending on who you are, the road to a diagnosis might well be one on which it's better to travel hopefully than to arrive. S and I were somewhat reassured to be told at various points that the 'obvious' diagnosis was not necessarily correct. In fact, we were even told with some certainty that S definitely didn't have Alzheimer's. Though it was clear many years ago that she had some form of dementia we found that it was possible to 'get on with our lives'. One diagnosis and 12 years later, I am happy that we had all that time together, sharing some great experiences, thinking that things might not be so bad after all.
Some people who are desperate for a diagnosis want it so that they can 'get on with their lives'. But you have to do that anyway and I would have thought it's a bit easier if you have some hope that you might not have a terminal disease (other than the one called life that we all have).
Some people believe that once they have a diagnosis, the cavalry will arrive with loads of support. Sadly, they are often disappointed at the length of time that takes. And people have sometimes been told, on diagnosis, that nothing much can be done for them.
Looking back, I don't think that an 'early diagnosis' would have been a good thing for us at all. I actually believe that we're still benefiting from the fact that we had so many good years. And all that time, S had Alzheimer's - apparently. Well, maybe we can still have some good times.