50-60 hr workweeks aren't uncommon, especially including oncall stuff.
As a new grad in the US(If you live in a lower cost of living area, things are probably more spread out so you probably need a car since the public transportation is usually limited in those cities and everything is 10miles away from each other. That's several thousand dollars plus insurance and maintenance.
Besides the costs of living, keep in mind that many people are paying off student loans into their 30s and 40s. A salary looks a lot smaller when you're 150k in debt.
When I was still in college, my health insurance out of pocket was $350 a month. Now that my company pays for health insurance, I pay $100, and that's as a non-smoker at a healthy weight with little family history of cancer/heart disease, etc. I imagine those that are older/heavier/less lucky with genetics pay more for health insurance. I still have to pay a few hundred dollars as a deductible if I go to the doctor.
I guess I'm just throwing numbers around but my point is, it adds up. Also the peace of mind of not worrying about affording to go to the hospital is a non-zero value.