The thing about noticing what you need is: it's a never-ending process.
You might think that you've got the perfect routine to support your writing practice, for instance.
But if you keep paying attention, you'll find that -- maybe gradually, maybe all at once -- it doesn't work anymore.
It might be only certain elements, it might be the whole shebang.
You'll notice this same phenomenon with your go-to tricks for soothing and calming yourself when you're upset.
Or your tried-and-true methods for keeping your body feeling good and energized.