Today, when visiting my landlord to pay rent, I was given the invoice for an ongoing exterminator's treatment in addition to the usual billing. The landlord proceeded to mention multiple payments as an option.
I called the bank to check my balance, just to see how healthy my Stash was before asking it to speedrun this bill that would total--with rent and exterminator--almost $1000. After all, I'd recently used a chunk of it to buy a bike (because I was tired of my expanding waistline and the taste of Mr. Money Mustache's fist; it was long past time to finally do something about it). And thankfully, it could handle the bill without even dropping below five digits. So, I immediately paid off a bill that was expected to be done with payments, and it feels pretty good to know that I will have to deal with neither interest nor the mental overhead of keeping track of it.
Though I haven't put in the effort to be a true Mustachian--around 30-40% of my income is stashed instead of 50-75%, which would be easily possible if I worked on my grocery habits--the benefits of even partial competence are encouraging!