Why am i writing?

I can understand why I'm writing my blog. Its so that my family and friends can know what i'm up to.
But I can't understand why i'm trying so hard to keep a diary.


Lately if feels like really lots of good things happened.
And i'm anxious to write down everything.
every detail.
To remind me I had fun.
I'm so afraid that I'd forget the fun things I've had.
why am i writing?
so that i can read back when i'm down?
isn't it good enough just to have fun
and let the memory be stored somewhere in the head(heart... whereverwhatever)?
i guess i just don't have enough confidence in my own memory