I'm gonna disagree with you lot. I had my work experience 2 years ago in year 10, i managed to find my own placement in an apple repair place called "amsys". Now, i want to go into computers, mainly fixing them like what i had done on work experience... and to be honest, im GLAD i did go. For the simple reason that i have learned that it isn't boring, you get to know the workmates and its a right laugh, i thought it would be good then get boring, but i would be happy to do that again and again.
I find them fascinating and can't wait to take them apart/put them back together again. Straight after i turned 16 i applied for a part time job there, but they hadn't any vacancies so it was unfortunate.
If you find something you want to go into, i would recommend trying it out.
IT DOES help, think about it, you WANT to do retail when your older, your spend your whole school/college/(possibly uni) life leading up to it, spend money and time on it. You get the job...and within a week your bored, want to do something different? All them years wasted, atleast if you try retail out now, find out you hate it, you can think of other options
EDIT: dam, that post got long quick
