Knowledge seeping away

I remember when I was in a different state, that I understood, life made sense, things just clicked in my head, I could see in a serving / aligned way. And after a while, it started to seep away. Like moment by moment I felt the capacity to look at life this way was leaking out of my head, like sand through hands. Because I just attended the vipassana course, I was inclined, even though it was hard, to honour the practice and to just let the disappearance happen. Slowly, over the course of minutes, my old self and familiar parts where returning.