Hi @jillsy, sometimes I tune out, but keep one ear open. My husband's stuck in his childhood mostly, having forgotten much of his past. Now he comes up with some fantastical stories about his parents, sister, etc. Sometimes I ask questions so we can converse and maybe get some insight into how his brain is working. I don't argue with him about his delusions. Other times, I ask a question to bring the conversation back to the present.

The one day I was on the phone with a friend and ignored my husband's obsession with the gardener leaving, he went outside to say goodbye, fell over a box left at the front door, and fractured his hip. Surgery, a week in the hospital and three weeks in rehab followed, plus a long recovery at home. That's why I said keep one ear or one eye open. Watch for changes. Sometimes, longstanding behaviors just stop. My husband's been meticulous about shaving, but this week he had a dental appointment and didn't shave beforehand, which I didn't notice until we were at the dentist's office.
He goes to bed early and stays there so I have a few hours of quiet time at night, to work on a hobby, read, watch tv and chill out.
As caregivers, we have to find ways to get through these trials with grace (as much as possible!), stay the course and, somehow, give ourselves what we need to keep going. All the best.