It is a whole new world. I did nothing (and I mean NOTHING) for like the last 6 months of medical school. Then, I jumped into residency where I was working more than I ever have in my life. There is no comparison between medical school and residency - none - unless you really were there 80+ hours a week, thought about and signed every order, took every consultation, and endured endless hours of nagging by nurses, punishment by upper level residents, and stayed up all night long on call, on your feet running, and collecting all of the information you could ever find on 20+ patients to present a book report on each one on rounds in the morning - and take the nagging and punishment all over again.
But, on the bright side, I think I've learned to anticipate the nagging and punishment, streamline my work, become more efficient, formulate quicker plans, and actually become effective at PRACTICING medicine. I think there is less stress in residency because you aren't studying to ace that next exam or practical. Every day is a practical and each patient is a new board question. You learn to manage as effectively (and efficiently) as you can to make the day go by. I find that I am actually wanting to learn more for the sake of need, then feeling like i have to learn for the sake of a test, which is quite rewarding for me. The learning curve is very steep and can be overwhelming at times, but is the best education I have ever recieved.
EM residency is tough because each month there is a new field of medicine to practice, new systems to learn, new nurses to meet and endure, new residents with new expectations, and different challenges that you never learned in medical school but are expected to have mastered because of that MD behind your name. Think about starting a new residency each month for a year - that's sort of what it is like. It's like third year of medical school on steroids with the responsibility that comes with being the MD.
Don't expect to know anything from medical school when you start, and don't make any comparison to school. Residency is an animal that will take you time to tame - but it will be your best pet for you to love and snuggle with.
I'm done with the after school special analogies - get ready for a ride...