I can't say I ever felt like that during school, Uni maybe a bit but not school. My final school year was stressful during exam time but that's to be expected I guess since my uni application hinged on my exam results.

But having said that I imagine it could feel pretty different depending on what expectations you set for yourself, or more importantly - what expectations your parents set for you. If you've got mum and dad looming over your shoulder 24/7 pushing you for more so you can be a doctor/lawyer/CEO/whatever then you're probably going to feel pretty differently about the whole situation.