I follow the same principle for journaling. With the exception of rare challenges I go through, I don't have a schedule, or a ritual, or a particular place or time to journal. I journal whenever I feel like, wherever I feel like, and write whatever I want in it. And it works for me, because journaling is supposed to be personal. Us humans have whims and fancies, so why shouldn't our journals?
How many of your whims and fancies go in your journal? Does your journal reflect the pattern of your life?