My boss is this way, miserable all the time to most people. Yet, I remember when he wasn't that way so perhaps there is an underlying reason for his unhappiness that you don't know of. If you only see this person at work then you cannot be the judge of what type of personality he has at home or on the weekends. Don't get me wrong...I hate this type of person and I believe that you create your own happiness, it's just all in how you look at it. Have a positive approach to things and you will be a more positive and happy person. You have to take the bad with the good and roll with it. Find the silver lining...blah blah blah ginger.
Smile lots - you'll be amazed at how many people smile back.