How can journaling help you?

What do you think of when you hear the word JOURNAL?  Is it a sticker-covered notebook filled with your childhood scribbles? Flowers, hearts, rainbows, and peace signs? Or is it a lock-and-key diary where your wrote your deepest feelings about your first boyfriend? And hid it under your mattress, of course.  (Mine was orange with a little gold key. 🔑