I am 18 and a senior in undergrad studying Marine Biology. I have a 3.99 GPA. So, listen to me when I say this: When you say, I really need to focus on this crap- The only thing you want to do is watch TV. Take a 15 minute break after every 2 hrs of studying, and on those 15 minutes, visualize yourself getting hundreds on your exams. While you're studying, break up the material into chunks- and repetition repetition repetition is the key. Find little memnonics and 'tricks' for remembering something. Also, stay as relaxed as possible, and don't pull all-nighters. Good Luck! I'm sure you'll do great!