Unlearning is hard. I noticed it myself when I upgraded (clean install, ahem) to Lion over the last weekend. I used the whole weekend my Mac Mini with Lion and no other computer. It took these 2-3 days to get used to the "natural" scrolling in Lion.
The strange thing happened on Monday: When I scrolled on my work computer (with Windows using scroll wheel), I really felt that the text moved in the 'wrong' direction - unnaturally.