An example of how your impressions can be altered - I was on my blog a couple of weeks ago saying how Mithalwen* looks exactly like Georgiana, Duchess of Devonshire in a famous portrait; I'd just noticed this look-a-like. Last week I popped over to Chatsworth and the same portrait was there, and I thought "Oh, it's Mithalwen" instead of thinking "Oh, that's the duchess".
*Mithalwen is free to deny this resemblance of course
