A way of signalling the last item in a list of items where the first item is preceded by "first off". Use when you want to be sure that you're introducing people to the final and most important item in the list of bullshit items. Using last off shows your audience that you have prepared and you are not just pulling things out of your ass.
Last off, my students will learn about self respect. You think anybody thinks I'm a failure because I go home to Starla at night? Forget about it!