The cage I do not know what the cage is for Smashing Pumpkins. People in our society identify with that image of the cage in many ways. Many find themselves in cages created by the expectations of other people. Many feel they can't really be themselves because of pressures from society and family, of university and friends. That is a very real and very common cage.
Vampires suck blood.
It may be time or creativity, individuality or money. This generation is the first for over a century not to have a higher standard of living than their parents. If you are an X-er, you have prospect the of supporting aging baby boomers with a smaller population base and less money. If you are an X-er, you know you have great creativity and energy but few places to go with it. That's a cage.