When teaching ‘Introduction to Meditation’ workshops, I often begin the session with a question: “What do you think of, when you hear the word meditation?”
A common answer is “emptying the mind.”
Let’s explore this idea. Can the mind really be “empty?”
The simple answer is that the mind is never vacant. In fact, if it was to be empty, I would be gravely concerned…
When we practice meditation, we practice flexing the mind so it is able to be fully present and engaged in the moment. That is to say, a rigid mind gets stuck in its own made-up loops. A flexible mind does not. Therefore, we are not trying to empty the mind as it holds so many treasures. Rather, what we wish to achieve is a way to quiet the whirlpool in our heads by way of purposeful relaxation. We do this the same way we practice yoga: by slowly taking on mind “postures” and examining them. We observe, and we let go. It is a practice that takes time. The more we do it, the easier letting go becomes, and we can obtain control which allows us, in turn, to be present. Thus meditation is not about emptying but rather about having a mind engaged in the moment. This allows us to write, sing, dance, work, and play, all while being in a state of meditation.
Another common confusion is the difference between meditation and concentration.
Concentration is a milestone on the road to meditation, but these are not one and the same.
I will leave this as a topic for another post.

Whirlpool image by Hellbuny (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons
You mention that the mind can never truly be vacant. While I hesitate to raise your level of concern, I am quite sure I have seen signs of vacancy within the mind of our current president and many members of congress. I try to silence that notion when I drift into my morning and evening 10 minute meditation.
I can only refer you to another post here: https://todayslearningjourney.wordpress.com/2017/09/01/what-is-really-namaste/