In addition to car blindness, I think I must have Granada!Watson blindness – I absolutely cannot tell the difference between David Burke and Edward Hardwicke. I just watched The Final Problem followed by The Musgrave Ritual and it wasn’t until the end credits ran that I realized we’d switched Watsons!

On the left, we have Watson #1 (David Burke). I think? And on the right, it's Watson #2 (Edward Hardwicke). I'm pretty sure...
When put next to each other like that, it’s quite clear that they’re two separate people, but watching them in the series, I have no idea which one I’m watching – or even that I’m watching a different one!