I have all my physics/maths notes that could be in any way relevant, even though everything that's in them is also in the text books I have, in a more legible and coherent manner, basically because I don't like throwing stuff out and felt I had a half-way legitimate excuse for keeping those. I threw out all my Chemistry notes, though! ;) And I have a few bits and pieces of random stuff all the way back to primary school.

Never throw anything away, ever - you'll only regret it! That's my motto (and the reason I need a 4-bedroom house with double garage to fit all my junk in....)

If you really, really want to reclaim the space, you could start a mammoth scanning mission, and then keep it all electronically....?