I started teaching the astro option to my second year SL class last week and discovered something interesting. Very few students (and I guess very few people in general) know that the planets are not fixed in their position relative to the stars but move around on a sort of spiral path. However they all knew that if you were to look at the solar system from a long way away you would see the planets orbiting the sun. So students know what the solar system looks from from a place that no one has ever been to but do not know what it looks like from home. That struck me as quite odd but is a nice example of how we get knowledge, not from our own observation it seems.