From Sogen:

Curiosity is a skillful attitude in Zen practice. Cultivating curiosity, inquiry, investigation, questioning, wondering, asking, exploring in your practice leads to new insights, new perspectives, new understanding, and new questions. A useful practice question is “What is it?” Or variations on “What?” Try using it to investigate what happens during service: What does that line from the chant point to? What is the purpose of bowing? Using it to explore zazen: What is zazen? What is concentration, settled awareness, letting go of thoughts, letting go of the witness? What is happening right here and now? What is “ease and joy” in zazen? Using it to look into your inner life: What is this feeling I’m experiencing? What are the roots of this feeling, this thought, this daydream? What is “I?” Using it to look into the dharma: What dharma teachings can I see in my relationships? In the news? In our culture? In the natural world? Practicing with curiosity, wondering, noticing, inquiry can open your practice in new and unexpected ways. Give it a try if it’s not already a regular part of your practice life and enjoy!