If you only shoot B&W out of the camera your choice is gone.
Not quite accurate. If you shoot in raw (NEF), all of the color information is in the raw file, even if you choose monochrome in the Picture Control menu. If I am correct, I believe that if you shoot in raw + monochrome and open the raw image in an application other than Nikon's own, the image will be in color as only the Nikon software has the capability to process Picture Control settings.
B&W can certainly add drama and a sense of stark reality to an image. The ability to "see" in B&W is something that many more experienced (older) photographers that grew-up shooting film (anyone here remember Verichrome Pan?) have mastered. I would advise reading the 3-part series of books by the master Ansel Adams: Camera, Negative and Print. While these books, originally written 60 years ago, reference film, much of the same principals can be applied even with today's digital capture cameras.
B&W photography has seen a resurgence recently, and has become quite avant-garde amongst "artistic" photographers. For many of my fellow "older" photographers, B&W was the only practical medium available as color films, and the associated process, was simply too expensive. B&W also gave photographers total creative control as it could be processed and printed cheaply, and easily, at home in makeshift bathroom darkrooms without having to rely on the talents of outside labs. Up until about 20, or so, years ago newspapers (remember newspapers?) used strictly B&W photos. Color was reserved for the glossy monthly magazines.