header files in C

Should you have to include a header file into its own library? I can't understand why I sometimes, but not always, get compile errors because it's not getting the header file prototypes before it compiles the libraries.

>>16
Too bad your CPU is slow as fuck.

Time spent actually executing the program is nothing to the amount of time spent building it, if you're paying the developers that is. Interpreted languages cut development costs, increase revenue, and provide ENTERPRISE CEOs with better parking spaces. DOWN WITH C!