Living without money isn't easy, and making music can be an expensive hobby.
If you don't make any money, then things can become quite frustrating as you won't be able to turn all of those great ideas into reality that may have been spinning around in your head for years.
Having some cash in your pocket makes a lot of things much easier. While there are many ways to make money as a musician, you'll soon notice that it will be very, very hard to make it with music alone.
At least as long as your first killer album that will sell like crazy isn't ready yet of course.