I think that pre-clinical years might have been easier coming straight out of undergrad, but the work experience I had before med school definitely helped me in the clinical years. That being said, I agree with what previous poster said in that no one has been exposed to the volume of material you're exposed to in med school, so everyone is definitely lost for a decent amount of time either way. I don't think there's anything you can do to prep yourself, and if you're interested in what people think you should do in the meantime, read one of the million other threads on the issue of pre-studying vs not. My opinion is that pre-studying will do you more harm than good.