First of all, I will address the "I feel I have probably heard the answer before." I have asked the same question to teachers, just to hear the difference in what they say, to assess their understanding of this particular question. I understood more clearly where that particular teacher was coming from by their different answers. So, I don't believe in the feeling that you have already heard the answer before, I think that idea could limit you, and also limit your ability to learn. We have to be careful about thinking we all know the answers to everything, because we are always changing as well. Perhaps the question I asked when I was much younger and the answers I got, I understood it in a different way to how I understand it now. So, we have to try to be open to our changes, and we also have to try to be open to perhaps our teachers' changes. Hopefully they are changing as well! I wouldn't like to freeze anybody, and I wouldn't like to freeze my understanding either, thinking that just because I have heard one answer, that I know it forever.
How do we stimulate the mind when it is blank? One thing that stimulated my mind when I thought that I didn't want to ask any questions, is to bring to mind when the Buddha talked about Kamma in the scriptures. In the scriptures it is recorded that he said that if a person visits teachers and doesn't ask questions, wanting to know what is profitable and what is helpful to practice, then this person may be reborn stupid. And that is one thing I don't want to be reborn as - stupid! Because I believe asking questions is a very important quality to help guide us through this life, and through the world. Because we have to make very important decisions in our life that affect our peace and well-being, and affect the peace and well-being of who we are going to become. So, usually when I felt blank and I brought to mind this teaching on Kamma, it stimulated a lot of questions.
One thing that can stimulate questions is to ask your mind a question: "Am I free from greed, am I free from hatred, am I free from ignorance?" "In what areas in my practice do I need more help?" That is another question that can stimulate some investigation, because in order to stimulate questions, we have to investigate into what is happening for us. So, "What aspects of my practice need some help? How can I improve in this particular quality?" Perhaps go through the Paramis, perhaps ask yourself the third question that we often ask: "In what way can I improve in Generosity? Now does this person have some answers about how to do that?" Go through all of them.
So, basically when we are blank we have to bring up the investigative quality of the mind, ask a question of the mind and get the mind on our side. Because if you ask it a question, the mind usually wants to answer it. So you can try that and see if it works for you. But certainly remembering the one about Kamma worked for me. I hope none of you want to be reborn stupid!