Most of us in med school are pretty good students and pretty dedicated studiers. I don't really know anyone who actually slacks off - if someone is taking a weekend or night off to relax/party/sleep/ski/doanythingbutstudy, you can bet they busted their hump (is that a real saying or did I just make that up?) the week before or the week after to make up for it. So I know if someone is behind in work it's not because they've been slacking off or not putting in the requisite time.
No one wants to be behind in work - and a lot of us med students are pretty type-A (shocking, I know) and ideally would like to be ahead. But it's absolutely impossible to get ahead, and sometimes barely feasible just to stay on top of everything. Constantly feeling like you're playing catch-up is exhausting. It's also exhausting to finish an exam and then have a podcast and quiz due later that afternoon, or have to get to the hospital two hours after the exam for your preceptorship - there's no down-time or a moment for a mental deep breath.
Thankfully second year and its constant tests lasts only two more months - and then it's time to study for The Big Test, aka Step 1 of board certification, aka the test that determines the rest of our lives - no big deal. But at least we can make our own study schedule for that and take breaks when we feel like we need them.
I expected med school to be slightly soul-sucking, but I'm not sure I expected to feel so tired before third year and rotations even begin (and when I never get less than eight hours of sleep a night, ever).