I only did it once as a child but I was kind of forced to by my dad and I really hated it because it was like a homework assignment from him.
I have no idea why he did that. Maybe it was so that I can improve and stay on top of my handwriting skills. I don't know.
I just wrote stupid things like what I did, ate, etc. not my thoughts and feelings.
So, everyday I wrote one or two paragraphs or maybe half of a page at maximum because I didn't care.
Even if he didn't, I would never have done it on my own, honestly. I would have been doing something more interesting.