What if you lost all of your memories? For whatever reason.
You had to re-learn everything.
Talking, reading, writing, social skills, and such.
I'm not sure about you but if lost my memory for some reason, I would want to know who I was before it was all gone.
Partly out of curiosity, partly out of searching for the new identity I would be in the process of making (since going off of the shadow of your former self would help save time in an identity crisis).
What I acted like.
What I knew and believed in.
What I enjoyed doing.
What I was good at (seeing as many people who suffer memory loss can retain memories through old things, or at least learn them easier).
What mistakes I made.
Who I truly cared about.
What I truly cared about.
The more I think about it, the happier I am that I inconsistently journal, even the sad things.
If I lose my memory, I'll know early on to despise my pessimism.
Food for thought.