I've seen it a million times. Guys wearing all-pitch-black getups. Uniform combination of black shoes, black shirt, black jeans, black jacket, black watch, black scarf and black rimmed glasses. So yes, black is cool, and it's especially appropriate during fall and winter. However, I personally think you can always do better by adding a little extra color to your outfit, even if it's subtle. This actually applies to any color, since a little variety in an outfit can help it from being too boring or uniform. For example, here's an all-black outfit I'm wearing. The difference is that I wanted to add a subtle hint of color (some green and navy gingham on the shirt which together looks like black, and brown lining on the boots), and also distinguish my blacks a bit from each other. Notice my jeans are a lot lighter than the rest of the outfit, while still having that underlying black color to it. My scarf also has grey on the inverse side.
See? Denim on denim can sometimes work.
From a closer distance and with ample lighting, you can see that the shirt is actually blue and green, not black. Some red highlights on my watch as well.
Hmm, my Red Wing boot lining matches my coffee table.
I like to cuff my pants when wearing boots. Show a bit more of the boot.
Now, I still would prefer to wear a lighter shirt with an outfit like this, but if you want to wear all-black, my recommendation is to find some way to make each piece slightly different from one another. Or else it'll just look like you're in a black jumpsuit, since others won't be able to distinguish one piece of your outfit from another.
So go out there and continue to wear black (even though some will tell you it matches with nothing... which I don't believe in the slightest). But also remember it's okay to still have some color or differentiation in your outfit to make it more interesting. Grey can be a great friend in this case, and despite what people will tell you, brown can work marvelously if used properly.