I'm not sure what people mean by "Mind-Muscle Connection", but I have a small anecdote. I'd like to know if any of you have experienced this.
Some years ago I was on a bus, thinking about doing legs on the afternoon. In my mind, I was laying out my routine, exercise by exercise, set by set. Without even noticing, I was so inmersed on my thoughts that I was even thinking about how my muscles would feel while doing leg presses. Then all of a sudden I feel the same rush you get while you're lifting weights. It was amazing, without moving a single muscle, I had the same endorphin rush you start to get after 20 min of doing weights.
It's only happened to me once.