Heh..
I don't usually..
but i find that when my mind is racing.. and i've got nothing that i'm in the middle of .. I get ideas and thoughts..
better to have them in writing than wasted in my head.
I do most of my writing with/for other people .. which is why this forum is GREAT for me ... i love the writing challenges .. and feel that i use my pre-college writing skills fairly well.
so .. in a nutshell .. because i like people to read what i write.