I have been keeping a personal diary since I was about 13 years old. It's my private space to reflect on experiences, thoughts, emotions. It helps me to manage stress, anxiety! I highly recommend this practice!
Or, to just state facts and not actually bring in emotional states.
Some things are just best kept inside one's own head.
About 20 years ago I kept a more personal journal for a while. About 10 years ago, I shredded it.