Photography is about telling a story thru a still image albeit thru color or B&W. With color one can play around with different primers or secunders to show emotion, eg red for love or anger, even death. It's a bit more difficult to transmit that in B&W. Hence one need to understand about the effect of the 10 zones/tones (first introduced by Ansell Adams) to describe the story to viewers behind the shot. On top of being nostalgic in value.