Quick answer: A Blue Moon is the calendar's rare extra full moon, either the second full moon in a single month or the third of four in one season. It happens roughly every two to three years, which is exactly where "once in a blue moon" comes from.
Yes. If you feel emotionally off during Mercury retrograde, you are not imagining it. A lot of people notice their mood shift during this window. You might feel more sensitive, more reflective, quicker to react, or suddenly aware of feelings you thought were long gone. It is one of the most common things people mention when they call us, and there is a real reason behind it.
