If you're planning to enter med school, be sure to choose a pre-med course that has a medical background / subjects such as chemistry, biology, anatomy or in other cases take some science program of the course beforehand. Or else, be ready to bleed out (more like, hemorrhage) when you start your med school.
I never did get along with Chemistry when I was in my BS Nursing, all the more with Biochemistry right now. So how do I cope? Simple. Milk some guy who knows more about the subject and let him teach you. OF COURSE I'M JOKING! (Never do this, they might find out) :D
In med, you cannot thrive if you're lazy. Lazy reading, lazy studying, lazy eating and yes even lazy partying (You read that right, partying). You really have to read your books and allot time on studying. Another factor is a sharp mind and memory. This is your armor for battle. It isn't necessary to memorize everything, what's important is that you get to know the how-why-when-what mechanism of the subject being discussed, and of course not forget about it.
The mouth of the righteous man utters wisdom, and his tongue speaks what is just.