Stress
Compared to your sophomore year organic chemistry test, life as a full-time, employed materials engineer really isn't so bad. Or at least, it could be worse. You could be the astronaut instead of the aerospace engineer—there's a little more stress to that career.
As it is, you'll work an average forty hours per week and get paid for your overtime (source). You'll have time to meet friends for happy hour drinks and still have time leftover to go catch Junior's tee-ball game. And you'll work with other people who have those same not-stress-inducing hours. You'll have to meet deadlines, of course, but you should be able to keep that stress ball safely tucked away in the bottom drawer of your desk.