Strict Adherence?

The question about adherence to the sequence of the Primary Series came up the other day from one of my students. What happens when you miss a pose in the sequence? Is it ok to move on? Is it ok to do the omitted poses after the fact or does it disrupt the magic or intelligence of the sequence since it is a progressive order?
My best answer is...it depends.
The system of Ashtanga sequences like the Primary Series is a progressive, intelligent series of moving and breathing in the body. Each pose targets parts of the body to open to the flow of energy. The Primary Series is specifically designed to work the 'gut' of the body to clear congestion in the process of digestion. Ancient yogis believed that disease starts in the gut, therefore, making these poses important in the process of helping the organs of elimination work more efficiently - lots of forward folding to compress the gut. Movement is medicine. Each pose has a purpose.
What happens when we don't do everything in the right order? What happens if we leave something out?
The order of the asanas is important as one prepares you for the next. If you forget a pose, it is after the fact and can be added in if you like or not.
When poses are omitted consciously or unconsciously, you have a choice. You can leave it at that and make mental notes for the next practice to include them. But sometimes I like the feeling of checking everything off and tuck missed poses in when I realize I missed them- we always realize at a point where we’ve after being prepared for the pose. From a standpoint of readiness physically, we are ready after the fact as long as we are warm. So it depends on what you want from your practice that day. It took me years to give myself the agency to let my practice be my own. Eager to be in the system of ashtanga, I was rigid with the practice, but as I talked more with my teacher, David Williams, I realized that no one is watching and it’s about what feels good in the flow of my practice everyday and nothing external to me is judging or measuring my practice. David’s practice scales to his day and how he works on his mat each day. He wondered this same thing and asked his teacher, Pattabhi Jois (Guruji) did he have to do the whole primary series everyday except moon days. Guruji told him that as long as he did the minimum practice, he was in good standing with the practice. The minimum is 3 Sun As, 3 Sun Bs, the three lotuses and savasana. Seems minimal, but almost always our desire for a little more, adds a little more. What Guruji is saying is, as long as you practice, all is coming. The yoga will work with you and for you.
The system of ashtanga invites discipline and rigor, especially when you are new to the practice.
Learning and memorizing the sequences is a discipline. It’s a process of repetition that engravings the order of the poses in our bodies and minds. An eager learner, I would often feel defeated when I forgot poses in the sequence, which ended up demotivating me sometimes and motivating me at others to work harder. As a lifelong pursuer of perfection, it sometimes caused a suffering of "not good enough." I have been working on this in my meditation and asana practice since the realization that no one is grading me. Perfection is not real. Omissions, mistakes and corrections are real and part of the human experience...on and off the mat.
After more than 20 years, I still forget poses in the sequence - momentary distractions and sometimes I think a subconscious protection is real when we are dealing with injuries or conditions that make poses more challenging - I guess you could call it a subconscious blip in our will. I still mix up the names of poses. I still have a hard time allowing myself to edit the sequence to make the practice more nurturing, nourishing and sustainable. But, I have started making progress in the practice of forgiveness and building my own agency in my practice.
You will experience all of this in the lifetime of your practice.
The three lotuses at the end of the practice celebrate this.
The bound lotus represents the seed of our practice as we learn the mechanics of the poses, as we step into our desire to learn and we become familiar with the system.
The upright lotus represents us finding our groove in the system - knowing how to navigate the sequences and poses, becoming adept at bandhas, dristi and breath, and being in the flow and wholeness of the practice - blooming!
The ascending Lotus represents us being in the flow of relationship between ourselves and the practice - having agency to ebb and flow within the system to practice sustainable and personally to nurture and nourish ourselves.
So in the end, the answer is, "it depends." What are you practicing today? Being complete? Being compassionate? Being friendly with yourself? Learning from the successes and failures? Being sustainable? Being real? Being human?