Can’t write at your usual time? Sway, and write later in the day anyway.
A work project doesn’t go your way? Sway, remember your ultimate goal, and keep going anyway.
Can’t go for your usual run because your knee hurts when you woke up? Sway, realize there are more ways to prepare for a marathon than just running, then do a prep session anyway.
If you don’t want to let the day-to-day sway you in your purpose, you must sway with the day-to-day.
When things don’t go your way, sway – but find a way to make progress anyway.