Not Stages But Levels?

Dogen's Rules for Meditation say that zazen, just sitting, is not something that is done in stages. Maybe not but it does seem to have levels or layers not all of which are experienced simultaneously:

(i) uncontrolled surface thoughts that everyone perhaps is familiar with;
(ii) stillness when attention, undistracted by thoughts, is focused on the present moment;
(iii) deeper issues arising from or within the stillness;
(iv) resolution of deeper issues.

When I started to meditate twenty seven years ago in 1985, I experienced only (i), wanted to experience (ii) and did not understand references to (iii). Now, I have glimpsed (ii) and (iii) but have not come close to experiencing (iv). Meditation is worth doing but can take a long time. Dogen wrote, "If you want to find it quickly, you must start at once..."