I think this is a very common emotion. I know that I still feel it, and I am 55!!! I know that, with me, it goes back to elementary school days. I was a good student, but a shy child, and was afraid of making mistakes in class. I also was a homebody and lived for summer, weekends, school holidays and (best of all!) SNOW DAYS! In Massachusetts, when I was little, we seemed to have tons of snow, and there was nothing quite like the feeling of an unexpected gift of a “free” day.
I remember watching Sunday evening TV (Ed Sullivan and Bonanza, I believe) with a sense of impending doom - not only because TV was forbidden through the week, but because the spectre of school hung over my head. I felt the same when working, as well; had to get up early, get going, get out of the house and leave my nice “cocoon.” Even now, though most of what I do is on a volunteer basis, I still get that “feeling” from time to time on Sunday night, as well as at “back to school” time, though I haven’t been in school in 3 decades, and my girls are graduated and married. Some things just stay with you, I guess!