"Don't let the perfect be the enemy of the good." (Attributed to Voltaire)
I tend to look for the perfect idea, and of course the perfect time to write. The perfect place. The perfect mood. When I fall into that mindset, I don't write.
I'm striving to become a "good enoughist" rather than a perfectionist. Any idea, time, place, and mood is good enough to write.
Writing something, sometime, somewhere, anyway is better than writing nothing at all.