Should I be unhappy?

Why am I unhappy? In the previous post I wasn’t able to trace a single instance of happiness in the past. By and large every time I have expected it in the near future and I am this far by now. What is the reason which makes me assume that happiness is always in future? I, however, can’t ignore the experiences of the people who are senior i.e. already through with my stage, always look back to trace the glimpses of happiness in their past. That means I too will be unhappy in the future.
One conclusion comes here is that; happiness was neither there in the past nor would it be in the future, which means it is an illusion. Thus happiness is something unrealistic thing which can’t be achieved.
Another school of thought says that happiness can only be felt in fantasies. Fantasy theory can have a lot in its favor. I think everyone must have some, if not much, attachment with fantasy. I do have. Had fantasies been realistic even a few bit, I would have done plenty of crimes as well as number of heroics. But since fantasies are unrealistic we only fantasize the thing which we like. I would have become a Sachin Tendulkar on one hand and an Imran Hashmi (you are free to go beyond, as the topic is fantasy) on the other. I think these are two of the extremes of fantasy for me. But as soon as we return to the reality we are filled with anguish, dissatisfaction, unfortunate, guilt or gloom. Thus another animated form of unhappiness. So unhappiness is anyways is unhappiness.
So should I assume that there is nothing which can really be called Happiness? No. Yes! No, because in all this discussion I think I have completely missed something is called Present. Didn’t I? In the blind search of happiness I have missed a possible source or may be the only source of happiness and that is Present, the moment in which I am right now. Irony of the situation I am at that stage of life which is certainly and in fact the golden span of life. I am so fortunate that I am so healthy and completely blessed with everything. My body is completely backing me with power, energy, wit and health, which may not be the case in the years to come. I am in the prime right now and will always wish for these days in late years as people do. Why people wish to have young age when in their late years? Because the body, which is going to company throughout our life gives full support only in this age. Later on it will ask for care and cure.
Now ball is in my court again. There is no reason to live in past or volunteer in living future. In both cases I am loosing Present, which is certainly capable of delivering goods. Why shouldn’t I cherish every moment I live. All the unhappiness that comes in my way is because I take it that way, in other words negatively. Another reason is my leaning towards materialistic stuff, which makes me more and more desirous and thus unhappy. Being ambitious should be a problem but building a big palace of fantasies around those ambitions is certainly a big problem. Due to which we face a lot of mental discomfort. Ultimately at the end of discussion I can say that I am solely responsible for all unhappiness.
I am the source of all unhappiness, it is as good as saying, I am the source of all happiness. A half full glass of water can also be said to be a half empty one. Reality is simple and well known but the way we interpret it has made big difference, half full is optimistic one and half empty is pessimistic one. If I take the things optimistically and with least possible self interest, I think the amount of happiness will increase.
That is it for now.. Thanks and all regards to your comments..