Wonder begins when familiarity stops pretending it has explained everything.

Familiarity produces a feeling of having understood, and the feeling is what closes the question. You stop wondering about gravity, about sleep, about how a conversation transfers a thought from one head to another, not because you know how they work but because you have seen them often enough. Wonder returns the moment you notice the difference between recognizing a thing and understanding it.

Pick something completely ordinary and ask how it actually works. Follow it two or three levels down. What you find is usually stranger than expected, and the habit of asking makes an ordinary day considerably larger.