As others have already said there are no hard and fast rules, no definite sign posts on the Dementia illness road. I have read threads where a person asks how many stages are there in the illness? I have seen talk of three stages, five, seven, etc. The truth is no two people have identical paths with this illness, but the more it develops certain issues arise for most sufferers. Uncertainty can lead to anxiety about the future, which can make caring all the harder.
Truth is no one can predict with accuracy what will happen and when. Best to take one day at a time, deal with what presents as opposed to worrying and wondering about tomorrow. Enjoy what you can, talk to yourself when confronted with uncomfortable feelings, remember many others are facing similar issues. Come to this forum for advice, help, support, just to let of steam if needed. I know it can be hard not to be concerned about the future but then look at Coronavirus. Came out of the blue, added new problems and who could have planned for it or predicted it. All we can do is muddle through, trying our best for loved ones and others. What Dementia was already demanding of us, but demonstrating best to focus on the here and now.
please stay well and keep posting or at least reading the threads.