Do these moments of lucidity happen often?

My grandpa who is 85 and in about the 6th phase of AD has been very lucid for the past week or so. like he is back to his old self, trying to fix things around the house. Asking if he can go for a walk like he used to. We found him in the basement which he hasn't been down there for years. I know AD doesn't get better, but this is just weird!! He is picking up the phone wanting to call people. He has been doing this for about a week or so. He usually sleeps everyday for almost 17 hours. He only gets up if he HAS to. I have been his full-time caregiver for over two years, which is when he first developed AD. I have seen moments of lucidity like this before but never for this long or this consistently.