This is a rather serious question. Some things are important in life and some are not. I have written a number of series on deeply philosophical matters. Some of them are not practical in any immediate sense. They are also difficult to understand. So why should anyone care about such issues? What should people care most about in general? My answer is quite simple. People should desire what will actually make them happy.
There are many things that people think will make themselves happy. Sometimes this takes the form of material things: money, food, clothes, a nice house and a nice ride. These things will make us happy for a short while. We eventually become used to the nice things and want things that are even better. Some rich people in the world can have any thing they want. But there is no reason to believe that things are any different for them than they are for us. They still want better things. The only difference is that their money cannot buy something better because that better thing has not been made yet. Nor is there any reason to suspect that technology can solve the problem. Our desires for better things have never vanished or decreased with the advance of technology. So material things are simply not powerful enough to give us happiness.
In other cases, people believe that activities of some kind will make them happy. Perhaps they make us happy because they are dangerous, new, aid us in self-discovery or help us connect with other people. These activities really do give us happiness for a short while as well. The problem is that we will always be seeking new activities. We become used to an activity and it no longer makes us happy. A new activity must be sought that is more dangerous, newer, aids us in further self-discovery or helps us connect in new ways with new people. In spite of our creativity, there is no reason to suspect that this will ever change either. Activities are simply not creative enough to make us happy.
Still other people believe that friendship and other relationship will make us happy. This is a good suggestion as well. But once again, there is a problem. Our whole point in having relationships with other people to share our lives with them in some way. But the problem is that even though this brings happiness, even this happiness only lasts for a while. We either choose to gain our happiness from somewhere else, or we wreck our relationship. In order for us to truly be happy because of a relationship, we must share more of our lives in a greater way. We are never satisfied with what is shared already. But as more of our lives are shared, so is more of our mistakes, prejudices and evils. As we share more of our relationship with others, we are also less tolerant of them condemning us for our evils. But that is also inevitable. So our happiness in relationships turns against us. We are simply not good enough to each other happy.
There are yet more ways that people have found to be happy. But they all fall into the same problem. They give happiness for a short while, we become used to it and want more. There is no satisfaction in what we do have no matter how much we have. There is also some kind of limit to how much we can have. So it appears that we cannot be happy. Nonetheless, gaining happiness is of the highest importance. So how could this be resolved?