What is your "One Thing" (per Gary Keller's Book)

[Allan Smith]

Without giving away any secret sauce of your business, what is your One Thing (such that by doing it, your other tasks become easier or unnecessary) each day right now if you are following this structure? And why?

I'm struggling to think of mine, and I think real world examples could be helpful for all of us. Plus, you'll be more inclined to stick to it if you say to the "world" on a public forum!