Knots are often called one of the oldest forms of knowledge, and I return to that thought a lot
What is a knot? It's a way of existing for a rope. It's not a thing; you don't go to the hardware store and buy 50 bowlines to use around the house. You buy a rope. A knot is something you know how to do with a rope.
Tying a knot is a process. The knot-tier understands how to transform a cord from a given configuration into another configuration more beneficial to the situation. Knowledge of a knot means knowledge of a particular way that a rope can be related to itself, and how to perform a transformation into that state. We do not change what the rope is; we change its state of self-relationship into a more helpful one.
Therapy, likewise, does not change what you are; it teaches you that your self-relationship is mutable. To understand yourself as a rope, that might be tied up in an unhelpful knot. That you can find new ways of self-relating that are more beneficial, without losing anything about yourself. Untying a knot doesn't destroy the rope. It lets the rope become whatever you need next.