My friend arrived at Leeds university for a double degree "xxxxxxxx and business studies" and was told in the first week of college, so in the first year you'll mostly focus on "xxxxxxxx", so for your Business Studies part of the degree we just require you to get a real job, earn money, during your summer holiday - otherwise you will fail the course.
This was a bit of a shock, but after some mild panic he registered with a recruitment agency, went for interviews, training and worked most of the summer!
he enjoyed the cash and so far is passing both xxxxxxxx and Business.
For you at school and your work experience, your teachers "might" be joking - but I have seen students quizzed on their work experience, like/love/loathe??? as part of their PS and University interviews. It's certainly a plus to have done it.