(UNSOLICITED) Back-to-School Advice

• No matter how much you know (even if you know more than your professors in a given subject --and some specific instances you actually may)...you can always learn something from them. It may not even be your subject content, but instead how they got to their current place in life, how they survived life/professional setbacks, how to behave while keeping real, or even how they've changed themselves in some way. Always look for something you can learn.
• Don't view your classes as some kind of sentence to be served, or hurdle that you need to get past. Too many students don't relish the opportunities they have to learn. Instead, train yourself to 'really get into' all of your assignments and projects, and learn as much as you can in the subject (independently outside of class as well as inside). Enjoy classes. Enjoy the opportunity to learn.
• An old teaching adage is that "Teachers do not give grades...students earn them." It's true. Be sure you understand how your grades are determined, (usually handled within the first class by reviewing a syllabus and class policy statement) and strive to achieve the levels/measures that are established. 
• When you are in a room with underachievers, and you are truly motivated, others may sometimes jealously criticize your desire to achieve. They may label you a "suck-up" or a "pet."  The best thing you can do is make them understand why you are driven (your goals, your passion for the subject, etc.) Push them to excel as well. The best dynamics for having a great class are where you push/motivate/compete with each other in a nurturing and encouraging environment.
• If you don't get something, don't let it go. Concepts in a post-secondary level build progressively, and you can get lost quickly. Be sure you make time to understand. Office hours, phone calls, IM, discussions with peers (etc.) all help. Most schools have study-groups or tutoring available as well.
• Everybody loves a go-getter.  Be one. Not a kiss-up, but someone who is motivated to achieve short and long-term goals, and isn't afraid to work hard to get them. Set your goals (what you want to be doing  weekly, monthly, annually, and in five years) and review them to see how you are doing at achieving them. If you are off, figure out how you need to modify your plans.