I'm sure it's different for everybody. Personally I loved
micro. Don't get me wrong, it was HARD, but it was so interesting that I didn't mind. I got really bored with pre-req classes like chemistry that were too removed from nursing--I was anxious to get to the good stuff. Micro was one of the first classes where we actually started talking about diseases and patient responses.
I credit a lot of my interest to the professor, though. He was this big fat German guy with a walrus mustache who looked like Wilford Brimley and said stuff like, "Den you put de vater in de winegar." He was a little too into STD's and once spent an entire class showing us slides of chancres and syphilis. EW!
When he was explaining the difference between bacteremia and septicemia, he said, "Now vit de bacteremia, the bacteria is a-knock-knock-knockin' on de front door of de cell. But you don' vanna open de door!
If you open it, den you got de septicemia!"
He was so weird and so funny that I could not WAIT to get to class every morning and hear what he was going to say. He was also really cool about giving you partial credit on test answers if he saw that you were trying to apply a sound principle or were trying to reason something out but just ended up with the wrong answer. I studied my ass off for the final--I can't remember ever studying harder for an exam--and I barely got a C. And I was damned proud of it.
Seriously, I hope you get a good instructor. Study hard but enjoy it too.