How to be passionate (when you open your mouth)

Vijay recently asked in the comments on a recent talk:

Thank you for a great presentation.  I noticed that your energy was explosive and  there was absolutely no point in the presentation where I could detect a lull. I am interested in learning if you have any secrets or techniques in  maintaining the focus of not just the audience, but also  yourself as I often space out even when I am working on something that I am passionate about.

Explosive energy makes me think of being a drummer in...