Stages are only milestones and there are many variations to be found between and beyond.
We all regress in certain circumstances.
The stages are a description and there is no right of wrong.
Moving does not correlate with levels of intelligence.
I found myself in a conversation once with someone who told me I was finding my faith and not losing it, I'm glad I had that conversation! An understanding of my personal growth has helped me understand that as soon as you think you have the answers, new questions and new doors open that's the beauty of faith.