When we think about an experience, we're calling up a complex set of circumstances and interrelated elements of what we've done before and how we felt about it. Songs, smells, sights all have the ability to take us back to moments and to bring up emotions.
Our experiential memory is so complex. We can use a physical place to bring up a specific feeling tied to that place. If we're romancing someone, we can create positive associations by creating experiences we're part of. We can imagine a place, or think of a face, to bring up joy or pain.
This gets more complicated when we have experiences that contain both joy and pain. Or, more simply, a learning experience or a skill that's associated with discomfort. Perhaps we've had a difficult phase of our career or a difficult relationship. If we associated all sorts of events with that time of life, it can be attractive to just throw all of it out as we move on.
If we can learn to slow down and pull apart all the different aspects of our experiences - physical actions, environment, emotions - we're better equipped to pick and choose what to take with us, how to grow.