when i was in school, the books i brought could fit into the
size of a small document bag...
everyone else had super-huge bags...
when i looked in their bags, there was a lot of crap in them...
their pencil cases could double as Transformers and was heavier
than a brick.. they also brought enough writing instruments for the
whole class in every colour of the rainbow... a few even brought
those desktop-type sharpeners!
then for each lesson, they were not content to bring just the book,
they had to bring the parts A and B of the book, plus every damned
exercise book they ever had to use for that subject.. and spare
exercise books, spare paper... one or two even brought their
"assessment books" along...
lastly, their bags... alone and empty, their bags weighed more than
mine filled...
could ALL THAT be the case for your inordinately heavy bag?