Yeah, you're right. They are very soothing and comforting. Sometimes an episode even reminds me when i watched it on the Sunday night mystery movie when i was a kid in the 70's.
Oh my gosh! I thought I was the only one that did this! I have episodes on my tablet and almost ever night I watch Columbo episodes!! I don;t listen to them but actually watch them while I'm in bed!
I've done it with a lot of things, but seldom Columbos, I think. But there's at least one exception. I always liked those CBS Late Movie reruns (in spite of all the editing), and because of having insomnia I usually made it to the end and much later. The exception I can always think of is REQUIEM FOR A FALLING STAR. I started falling asleep right after Nora heard the news in the restaurant. (Since I'd never seen it before that I can think of, I thought her surprise - that it happened to Jean instead of Jerry - was for real.)