Does having true happiness within ourselves, mean we are happy all the time? No, it does not. We have a whole lot of emotions; such as anger, sadness, being happy, irritable, or excitable, etc. Take the example of road rage; there I was driving down the highway to the coast, and an idiot drove in front of me, slammed the brakes on repeatedly, then dropped back and drove by my side trying to get my attention, then tailgated me. Was I happy? No! I was furious! I could see an accident happening. But I stayed focused on my driving and ignored him no matter what he did until he stopped playing with me and proceeded to do the same thing to another car.
It is human to get angry, and believe me, I got very angry, it was quite dangerous what he was doing. Once he drove off, I ranted and raved on about it for about ten minutes, then reverted to my true happy self. I let off steam, and took responsibility for my happiness and enjoyed the rest of the day. I controlled my emotions; I did not become a slave to them by remaining angry the entire day and being miserable.
We have emotions that are appropriate for different situations, and there is a time limit to how long we need to express our emotions in each situation. People who concentrate too long on negative emotions become stuck and forget to take responsibility for their emotions, what they need to do is; center themselves back into true happiness.