With 17 years in the Marine Corps I cant envision EMT school itself as being too much trouble. A lot of the training is hands on and done in a see it, practice it, test out on it manner that's similar to the way things in the Marines are taught, except in a far more easy going manner. The hard part comes in knowing WHY things are done and when something is appropriate to do or not appropriate, as well as developing critical thinking and decision making skills.
In the field you will find things far more confusing and chaotic than how things went in class. Patients don't cooperate, often have an altered mental status, bystanders and family are just as likely to get in the way and make your job harder as they are to help and provide useful information, and can sometimes be downright hostile. Sometimes they have it in their head that THIS should be done, and if you aren't doing what they expect(or saw on TV), they want to know why you aren't helping the patient. The weather and conditions you face can be just as big a problem as the patient's medical condition. For instance on the way to a scene you will frequently be facing the same weather conditions that caused the accident you are responding to.
At the EMT level you will often find yourself in situations where a patient is in bad shape and deteriorating, and quite frankly you don't have the knowledge or the tools to do much about it. You can be in EMS for years and still continually run into situations where you learn something new or see something you've never seen before. You will run into candidates for the Darwin awards on a regular basis.
Practice doing run reports, going through what if scenarios and thinking through what you would do in certain situations, and don't expect the best case scenario, always be prepared for things to not go right and to go south quickly. For instance think of what you are going to do if the patient you are extricating from a wreck stops breathing or needs to be suctioned, so if it happens you aren't caught with your pants down.
Understand that in the real world things are never going to be as simple and clean as they are in the classroom. You wont always have a patient lying flat on their back who needs to be spine boarded. They may be lying in a crumpled heap halfway down some stairs with their neck at an unnatural angle, or may be soaking wet in a bathtub with a fractured pelvis and covered in feces(both examples of things Ive run into). In EMS those people that can improvise will go far, those that cant will probably get burned out quickly.
Practice the basics like taking vital signs so much that you become an expert at it, and search out other sources of information like nursing text books, because so many of your patients are going to be medical train wrecks and have a long history of medical procedures and have devices you should be at least somewhat familiar with.
Remember that in EMS its 99% BullSh*# and 1% oh Sh*#, not unlike combat.
