Are you a bit of a twitcher? One of my friends when we are at Aberdeen University was really keen. I always felt it was a real shame that he was profoundly colourblind, not just the common red/green form, and couldn't fully appreciate the "beautiful plumage", to quote Python, of many of the birds. At mealtimes I had to tell him which bottle contained tomato sauce and which was brown, as they were unlabelled.