The comparative aspect of our mind can be pretty tricky.
It been integral in our continued survival as a species this last 160,000 years. Yet when allowed to run unchecked, it can lead to some unintended consequences.
I am fortunate enough to teach Ashtanga to several beginners each month in the Intro to Ashtanga Yoga intensive, and in many ways I envy their 'beginner's mind.'
Not that they are all neophytes or novices to yoga asana practice --- many have practiced --- but they get to learn the intricacies of Ashtanga for the first time, and don't have much previous Ashtanga experience to compare.
On the other hand, I've built a modest library of experience on the mat --- a byproduct of which is expectation.
Usually sharply followed, of course, by disappointment, as those first couple sun salutations can be a real eye-opener.
It was always easier and more fluid yesterday, or last week, or last year, or in India, or when I was 30, or 25, or ...
It's easy to install the postures as a certain kind of icon in my head of how it should look or feel --- and if only I could get back to that!
Geez. Imagine if you had to run a sub-5-minute mile every day in order to 'practice'? Or deadlift 450 pounds? Or both? Or perform any other standardized and challenging physical feat?
That'd be a pretty tyrannical yoga practice, and I hope the examples above point out the pitfalls of trying to cling to conditions (identity, time, location) that are inherently impermanent.
I am not suggesting to not have standards to which we apply ourselves --- e.g. set sequences of postures --- just that clinging to a memory of their performance is to cherish the outer form at the expense of the inner experience.
It is quite helpful to have the tools of breathing, internal focus, and looking. Usually they give me some space and perspective, and quite quickly the nostalgia quiets down.
There is a common trait among the people who practice with me who've been at it 15 years or more --- usually they have significant others, careers, and families --- they're just glad to be on their mats in the mornings.
Jason owns and directs Portland Ashtanga Yoga.