Mixed feelings here, what is an "inner child?" Feelings of exercising creativity and spontnuity don't have to be "compartmentalized"... Just work that into your adult life. only thing that is different otherwise is obviously responsibility, that will never go away. You might have to answer to your wife as to why you chose to spend a whole Saturday watching cartoons, but as long as you make your needs known, that shouldn't be an issue as well.
I'm sensing you have problems communicating your desires(ideas, inspirations, etc) ... other than that, you might be feeling nostalgia. But nostalgia is mostly ignorance. It felt like good times at times because I was ignorant to how my parents struggled.
Amazing. Thank you