If you’ve never tried to lucid dream, but you think you might be dreaming and aware of it anyway, you can still perform reality checks in what you think is your dream. Remember, time swings wildly in dreams, so if you look at the clock, look away, and then look back to find the time changed dramatically—you’re dreaming. If you look at a book page that says one thing, and when you look away and look back it says another—you’re also dreaming. Another general rule is if you’re pretty sure you’re dreaming because you’ve already noticed a lot of cues that don’t happen in real life, it’s a good bet you’re having a lucid dream without intending to.