When your energy and attention are remorselessly drained away by real-life situations. When it's not fun anymore. When you can't come up with any ideas that excite you.

And sometimes, at least temporarily, it's when you are convinced that the idea you've been working on has been done many times before, by authors far better at it than you. Yeah, I know that every author will have a different spin on the basic story idea, but it can get really difficult to come up with any new spins that don't seem like a waste of everyone's time.

PJ


"You told me you weren't like other men," she said, shaking her head at him when the storm of laughter had passed.
He grinned at her - a goofy, Clark Kent kind of a grin. "I have a gift for understatement."
"You can say that again," she told him.
"I have a...."
"Oh, shut up."

--Stardust, Caroline K