Thanks to the man who invented computer, nowadays, almost everything in our lives is done by computers and so, the importance of computer has greatly increased. Therefore, I think a very important skill a person should acquire in order to be successful in the world today is how to use computer properly.
Primarily, the skill is needed because almost at every place, every time, where computer is widely distributed, uses computer in doing most of the things in our lives. For example, when we are students, we use the computer to do homework and presentation at school. We write essays and make presentations by using the programs in computer, sometimes managing a difficult program. The students who are available doing it do their work easily, while those who do not have the skill, experience hard time doing their homework. Also, people at work need to know how to use computer because, today, almost every work in companies is done by computer, for example, making presentations, printing papers, writing an e-mail to a co-worker, etc. Moreover, for the people who communicate with people who are in other countries, it is needed. Some people write e-mails to send information to people, while some use it to exchange their life and culture.
Also, the skill is needed because in future, computer is going to be used even more and more. There are people who are falling behind using computers and thus have a sense of alienation in current society(for example our grandfathers and grandmothers), but if the computer is going to be utilized even more than now, what are the people who did not learn how to use it going to do? There is no special solution then learning it later in time, and if not, they will experience difficulty in their lives.
In a nutshell, an important skill needed to be learned in our lives to live successfully in the world is putting computer to use because it is used in most part of our lives and in future it will be used even more. Therefore, people should try hard learning how to use computers.