My brother made a comment about how his kids will be mixed (racially) and I said "They will be?" and his response was of course that his wife is Vietnamese...and I had an Oh duh moment. I knew she was, but in my mind she is just T, not an asian-american. I do this kind of thing more often than I think is normal - maybe its because I grew up in a very diverse area, or maybe because like you said we don't interact with people as often as we used to. Either way race just doesn't register as "important" more often than not in my mind.