I always compare journaling to trying to solve a math problem with paper and pen. Of course you can do math problems in your head, but it's so much easier when you can express thoughts as symbols.
But the problems you're trying to solve aren't mathematical. They're emotional and perhaps even spiritual ones; petty ones and unexamined ones.
It's a great tool more people should use, not out of obligation, but because once you become aware of it, you'll automatically want to.
To me it is the act of turning abstract thought into concrete thought.
For this reason there is nothing wrong with talking to your self. you are taking thoughts which are always a bit fuzzy and turning them into solid actionable items. Writing things down is even better at this. But the best is teaching someone else.
But the problems you're trying to solve aren't mathematical. They're emotional and perhaps even spiritual ones; petty ones and unexamined ones.
It's a great tool more people should use, not out of obligation, but because once you become aware of it, you'll automatically want to.