This is bound to happen to a complacent practitioner, or a student whose teacher isn’t paying attention.
Getting off of a plateau can be a challenge depending on where you are going and where you are coming from.
Ascending from a lower level can be hard because we are faced with stripping outside of our comfort zone, even though we are fully aware that to move to a higher level means progress.
Some of us find it hard to progress.
Ascending to a higher level takes on a deeper sense of challenge because we know that this will entail harder, more intense work that is new. New = back to square one.
We are thus returned to the role of student, having to submit to careful, attentive study and practice. Practice being the key word.
So, it makes no difference what we know, because we must always strive to learn more and more, in order to keep the journey alive. Once we reach a destination the journey, by definition, is over.
So keep on not arriving.