I've unfortunately experienced that smoker's anxiety of watching the clock and counting backwards, which takes the fun out of it. After probably thousands of cooks, I've learned to give myself way more time than I need mainly to account for fussy pieces of meat, trimming taking longer than expected, etc. I also tend to cook more forgiving pieces of meat like pork butt. Pork butt is remarkable because you can spend as little or much time prepping it as you want, letting it rest as long as you want, and it still comes out great.