Nowadays people seem to switch schools, either because they have to, and certain schools only serve certain grades, or because they move to a different place or have some particular interest, but I was in the same school for 13 years.
In the summer you want fresh, light and sort of quick things; in winter you want things that are comforting, so your body really tells you you want to go towards potatoes, apples, fennel, things that are warm and comforting. And loin of pork.