Journey home

Today we drove home, 9 hours but through some stunningly beautiful scenery in the early part of the journey.
Our three nights away were much better than we had feared. My father in law has vascular dementia. We last visited at in August and he appeared to have very low levels of cognitive ability. We feared he may not know us on this visit . However he was vastly improved, he still had memory difficulties but was 100% more ‘on the ball’. He was cracking (quite funny) jokes , was making conversation, and was taking an interest in what was going on. It is unclear what has brought about the dramatic improvement , no medication changes and living in the same environment etc. Now my understanding of vascular dementia is that there can be declines in cognition that can plateau before another deterioration but I have never heard of it actually improving??!
If any fellow blippers can shed any light on this I would be most interested!
Still, what ever the explanation it was truly wonderful to see!!