I know there's no way of knowing if you see the same hummingbirds from one year to the next, but I think I may get some hummingbirds that have been to my house before.
Every year I put out about 10 feeders, and have hummingbirds from April through October. One year, I hadn't put my feeders out yet by April 8 because I had never seen one before the middle of April.
I was standing on my front porch, and suddenly, a hummingbird flew to the exact spot on the porch where I always hang my feeder. It hovered there for about 15 seconds, and then flew off.
I immediately put my feeders out, but it seemed to me that, on a covered porch, the only way a hummingbird would know to look in that exact spot is if it had been there before.
I'm checking the map every day, and expecting to see hummingbirds within the next 7-10 days. I know it's really spring when they arrive, and that summer is finally over when I haven't seen one for at least a couple of weeks in the fall.