Going between: I'm good at this job and it feels nice, this job is too easy and I'm bored, this job inspires nothing out of me, I see myself moving up and making more of an impact, I want a very different position in the same industry, I want a similar position for a different org in the industry, I want to quit and pivot to something else entirely, I want to quit and dick around some, I want to start my own business, and I want to go back to school all in 1 week, nearly every week, is excruciatingly tiring and leaves me incapable of reaching my full potential. So, no amount of brainstorming is going to put a dent in the issue. The only system that helps me is being more stoic/learning to be OK in the present and want for less in life. It sounds like you really love this guy though, so just let him vent and make sure he has enough hobbies and support to be generally happy.