If you haven´t read and digested Nietzsche´s works, you are still wanting in understanding modern philosophy, science, psychology, and several other "currents of thought." Nietzsche was a pioneer in those subjects, and also he the only thinker who dared to fight for the destruction of the old and detrimental values of repressive traditional thought (read organized Christianity) that kept - and keeps - mankind in its sorry state. Beyond Good and Evil is an accessible "Thus Spake Zarathustra" which should be read by everyone who has any impetus to improve that sorry state in which humanity, with its mindless wars, finds itself nowadays.
A must read for everyone.