The benefit of journaling is not just reentry, but that you begin to solidify the mental model into a concrete branching of possibilities that is tightly coupled to the specific problem. Your work becomes traversal and mutation of this tree. Several benefits accrue: you begin to see gaps in the tree, and can fill them in. You begin to have confidence in your mental model, recovering the time you used to spend going over the same nodes again and again in a haphazard way. In distributed systems in particular, the work is often detailed, manual, error prone and high latency - with a solid mental model you can get through a checklist of steps with minimum difficulty and high confidence that you didn't miss anything. This ability to take something abstract and make it more concrete on the fly is a critical skill.
Perhaps the greatest barrier to using it is akin to envy. We see others who apparently do this without written materials, in their head. I think we see this as evidence of intellectual superiority and harbor the doubt that using an aid like a journal means we are somehow lacking in skill or ability. This is wrong. Using an aid to map out complex problems isn't a failure, it's essential, especially for problems in systems you've never used before. Over time you may yourself build up your expertise such that you no longer need the aid, but that doesn't signal anything about your intelligence or ability either, only your experience.
Perhaps the greatest barrier to using it is akin to envy. We see others who apparently do this without written materials, in their head. I think we see this as evidence of intellectual superiority and harbor the doubt that using an aid like a journal means we are somehow lacking in skill or ability. This is wrong. Using an aid to map out complex problems isn't a failure, it's essential, especially for problems in systems you've never used before. Over time you may yourself build up your expertise such that you no longer need the aid, but that doesn't signal anything about your intelligence or ability either, only your experience.