Kindly, it's only a heavy subject if you make it so. I have always led a reasonably sheltered life by the standards of my peers, and yet matters such as teenage pregnancy, divorce, affairs, death, life-changing illnesses and accidents, abortion, adoption, and certainly miscarriage were matters I was quite aware of long before I left junior school.
The reason for this was the bulk of what I have listed happened to people I knew or knew of, whether this be neighbours, friends, family, people from church, etc, it was all out there.
I remember being quite taken aback when I was seven years old and it was announced by a girl in my class that a teacher had died. The teacher had gone on maternity leave and we all knew women had babies, however, during this time it was discovered she had a brain tumor. I remember my mum mentioning quite casually -albeit sensitively- that said teacher had gone blind (I'm not sure if this was before or after she gave birth) and I was quite au-fait with this as we knew several blind people so I knew people sometimes lost their sight. Then she died.
I struggled with this, not because she was a favourite teacher of mine (she wasn't, she'd been utterly vile to me and others when I was in her class aged 5) and not because she was still very young, but because she was a teacher and I'd never heard of a teacher dying before. Although I didn't know at that point what the word "absurd" meant, it very much sums up how I felt about being told a teacher had died.
It wasn't helped by the headteacher who officially announced her death in that morning's assembly, as she chose to say "Mrs X has passed away". I'd never heard that term before, and even though this was over 40 years ago, I can still remember sitting there crossed legged and wanting to shout out "WELL IS SHE DEAD OR NOT!?!".
However, on reflection, I realise now that some exposure to real life at a young age isn't a bad thing, because by the time we hit secondary school most of us took so much in our stride. Maybe the fifteen year olds of today are not so robust - I wouldn't know.