the thing I love most about really big high quality university libraries is the ability to go find a place somewhere in the back of the stacks, and then to walk around finding a collection of a dozen books that sound interesting of themes you like but are not necessarily conversant with.

then browse those books for the next 5+ hours. Really used to get the gears of the brain moving. Of course this was also before the internet and before having any money and after 5 hours I was lightheaded, starving, and not necessarily sure what I was going to eat - but in a good way for me.