What is forgetting an experience?

During my day to day life experience, i imagine myself with wisdom. That imagination make me take a turn to some other scene where i exist as an ultimate supreme seer and i feel touch of realisation i.e, i can even touch (or hug) that scene, things, people, everything there. I enjoy that alot. But i forget what was the most satisfactory imagination and i keep remembering that. I want to know : 1. What is forgetting an experience ! It is science or spirituality at the basic ? 2. is it like if i can control my imagination, i can get the understanding of the state of nirvana and Nirvana is already in me ?