That's interesting. I do the same thing. I need books I've used for later reference. My books have been in storage for a number of years now and I feel like part of me is missing. It's very frustrating.
I am in an apartment and do not have the space for all of the shelves I would need for my books. I need to box up those I am not referencing regularly.
Good thing is I can always rotate what are on the shelves and rediscover some books I've bought but haven't had time to read. Or want to reread.