This has to be one of the dumbest questions I’ve ever heard.  It implies that you can only be one or the other–right or happy.  In reality, you can be both pretty much all the time unless your being right is tied to proving to someone else that they’re wrong.  Now you’ve created a problem for yourself because no one likes being shown they are wrong–it makes them feel bad and puts them in the frame of mind to make you feel the same way.  This, in turn, can affect your happiness.  So, if you’re right and you know you’re right, keep it to yourself and be happy about it.  Trying to prove that someone else is wrong can only erode your happiness and it solves nothing.  As Dale Carnegie once said, “A person convinced against their will is of the same opinion still.”  So the next time someone asks you if you want to be right or happy, smile answer them with a very affirming yes; because it’s easy to be both.