I had no idea what this bird was when I saw it, nor when I was back home and had spent a couple of hours looking it up in my books and on line.

So I posted it on a local birding page. There, a kind person told me it is an immature Hermit thrush.

Although we keep lists of the birds we see in our back yard, I have never kept a personal life list of birds I have seen. If I did have one, this would now be entered.