Many times the photographers could rely only on the flash. The light could be so dim or so weird, and there is no other choice as to introduce your own light - flash, to be able record the moment or correct the light. Everything would be great if using flash is easy, but there are many issues that affect the final image. Wading the waters of the Internet I found a good article with examples on use of flash. It is called Flash Techniques, written by Neil van Niekerk. That's a good read and should clear up a few issues you may have had with your flash.