I have worked as a graphic designer for two years, known a few who have taken it as profession, and here is what I think,
1. It is not the same as being an artist. Designing, when you start working at least, is a lot more about what the client wants to see rather than your self-expression. Expect to be treated like a screw-driver, going over mundane edits time and again. Learn to accept this and move forward. If you are only getting into this because you love to be creative, think again.
2. Working under a boss as a designer can further cut back your freedom as you have to listen to what the client says and also what the boss is saying.
3. However, if you are really good, people will start coming to you knowing what kind of work to expect and this will make your work more enjoyable over time. Try and get into the drivers seat and find out the kind of works you want to do, and the teams you really want to become a part of. Only then can being a graphics designer be an exciting career choice. But you have to have the patience to grind through the earlier years