One skill won't do it. You may be majoring in chemistry or history or mathematics, and you may know a lot about that subject. A good engineer's career will be stifled if she isn't also a good leader, manager and communicator. You will advance only if you have the right mix of skills. That's always been true, but the right mix is even more critical in today's rapidly changing world.
Victory goes to the most adaptable.
So keep learning, explore subjects other than your major. And don't imagine that at graduation you've learned everything you need to know. The learned usually find themselves equipped to live in a world that no longer exists. This material is in the public domain and may be reprinted without permission.