The design world is filled with sharp corners and competition that piles as high as skyscrapers. So if you want to get into this world then you will need to be confident about your abilities as well as your persistence. Without these two you will end up flopping down and getting stomped all over by other who want the same position.
#1- Imagination and creation
In order to become a pro in designing world you will need a lot of imagination coupled with the ability to bring this into creation. Even if you have awesome ideas, there is no point and no recognition that you will gain without the ability to bring it into light (figuratively). To become an expert in the field you will need experience working on a plethora of different things and should have experience experimenting with even more different things, as well as failing miserably and learning from it. According to experts in the subject of ‘creating’, to become a pro graphic designer you need 10,000 or so odd hours. Although this number is up to speculation, it gives an idea of how much is expected of you.
#2- Switching between assignments and projects
You cannot be working full time on a single project for the entirety of your week. When it comes to working in a corporation or even freelance, you will need to juggle multiple projects and have the ability to flip on and off switches on your mind when you jump from one project to another. Also you will need to design a wide spectrum of things to learn what you are best at, and also to gain recognition from peers about your abilities. If you keep in one track then you will become good at that only but you will not be called an expert. It is ideal if you start to handle this spectrum right when you are starting off as you will also have a fresh outlook on everything and will be able to grasp the aspects easily.
In any market of this world, you need a sharp sense of survival to make sure that you can keep the position or go higher. It is the same for the design world (and some may say it is a rather brutal world in designing). You will need to learn new skills and techniques frequently and polish your own versions of styles to stay at the top of the game (or get to the top). So get your battle gear on when you want to enter this world.