School was not very stressful for me. I never had especially high grades, but didn't do that bad either (3.4ish GPA in undergrad). There were specific classes that were annoying either because of the content or teacher. I'm sure there was some temporary stress over a few of those finals, but not excessive.

Work is much more stressful and high stakes. There's no real structure, no contract or performance guide (like a syllabus), and I need this job to support my family. Getting another job would be very difficult.