It is said that the Buddha's definition of truth is "what works." His pithy statement points toward one of the essential teachings about truth also contained within the path of yoga: impermanence. Knowledge and information come into our consciousness at an appropriate time, enhance our being and when we've integrated the lesson, it passes. The intelligence to accept the impermanence of all experience is the seat of true knowingness.
Great joy can arise when we experience new layers of truth. It can be so enticing that there is the temptation to hold onto it in attachment and perhaps proselytize to others. We often identify with what we know. Every time you say that "this is the way things should be done", you close yourself down to the possibility of a new, perhaps more evolved, efficient or friendly way of being. You also distance yourself from those who do not know, increasing division along lines of right and wrong. Even in the world of yoga, we sometimes find ourselves debating about the "right" method.
If we look again at the Buddha's definition of truth as "what works", we see that what works constantly changes. Hence, we already have the basis for a relaxed, open understanding of reality. What works one day will not necessarily work for every day that follows, even what seems perfect will one day pass away and what's absolutely suited to you in a particular moment changes - try to hold onto it and a small part of you dies inside and remains caught in the past!
Throughout our journey in yoga, we have met many inspirational teachers. One of the most evolved states of yoga involves being both open to new information and ready to simultaneously let it go when the cycle is finished, that is, non-attachment even to the very knowledge which enlightens our lives. Even the great truths of Western science are merely hypotheses that are meant to be true for a given period of time, until refuted. Zen teacher Suzuki Roshi gives us the phrase "Zen Mind, Beginner's Mind" (the title of his influential book) to explain that in the expert's point of view there are no new possibilities for learning, while the beginner's experience holds all things possible.
In terms of your practice, if you "know" that your shoulder is weak, how will you approach certain postures? If you "know" that a particular teacher is good (or bad) how will you feel in the class? What would happen if you walked into every situation with a beginner's mind?
Knowledge in its highest sense satisfies our hunger for the spiritual, elevating us beyond our daily identification with our small self. Knowledge belongs to no one, but can be felt, experienced and uncovered by all - be open to it.