As an applied physicist wanting a better grasp of the mathematics I use, I'm working through Mathematics of Classical and Quantum Physics by Byron and Fuller. It's a Dover book, so it's inexpensive, and so far it has been enlightening. For instance, it uses the example of vortexes in a swirling bucket of water to help visualize the curl of a vector field.

Fire Hazard. If there were an emergency and the power went out, the last thing you want is haphazarly placed immobile objects (in the dark, no less) slowing you down on your way out the door.