Writing a journal feels juvenile. That is the beauty of it. Even as you write the words, you cringe in anticipation of how an older, wiser version of yourself will probably ridicule you later. You can almost hear the self-criticism, faintly echoing in from the future. That’s why the thoughts seem childish as soon as you transcribe them into alphabetic forms.
Maybe this is exactly why journaling is important. It is a glimpse (or whisper) of your future perspective penetrating the present. You see your thoughts not only as you feel right now, but also as you might recall them later. As soon as your emotions inhabit a written work, they begin to exist outside of you. This creates a perspective that is invaluable — even if it is transitory and intermediate — and is worth all the supposed inward shame that comes along with writing your innermost thoughts down in the present.