To be precise: med school is (comparatively) a walk in the park. Years 3 and 4 of med school are a sort of "residency lite" where you rotate in different specialties, but the doctors don't really expect you to be useful, so it's fairly low-pressure other than odd hours. Study up so you can know what you're talking about, don't get in people's way, and you'll be fine. Residency is when the 80+hrs/week institutional hazing happens.