Honestly, for me the biggest roadblock is feeling guilty for skipping days. Like, right now I haven't journaled for a week at least (but I'm too anxious to focus on anything). I feel like it's a skill or a habit - forgiving yourself for momentary failure, and then coming back... And shame and self-consciousness. It's hard, but I think it's necessary to reinforce in oneself the understanding that it doesn't matter how much or how little you write - no one is going to judge you, unlike in other pursuits... Perhaps for someone like me those are the important parts of journaling - self-forgiveness and un-self-consciousness for when you fail.