I've kept a diary since I was like 10 years old. But my diary entries didn't start to sound depressing until I was 14. When I was 15 I remember coming from school one day and seeing like 4 of my diary entries sitting on top of my dresser (I'd sometimes write it on a sheet of paper and I always kept it inside of my drawer). Needless to say, I was hysterical! lol. I later found out my brother had went into my drawer looking for money; he claimed he didn't read it. I didn't believe him though. I went to school the next day STILL crying about it lol. I'm a VERY secretive person, so to have somebody know my most inner thoughts was just... gut-wrenching. Instead of writting my diary entries on paper, I now write them on my computer and just save it to my thumb drive (you'd have to know my password to read it). Maybe you should just do that.
I did since 15.
I'm curious to see if it's common for sp. .
I started keeping a journal when I was 11, right when I developed my social phobia. That's when I started getting all of the negative, self-loathing thoughts and I needed a place to write them all out. I still have the same journal and I'm almost done with it now. I'll be sad when I use the last page..