Why the Moon was called mystical
The word can sound like fog. In Jyotish it means something exact.
The Sun is the wish to be seen. The Moon is how the day actually feels: sleep, habit, mother, food, the private weather of the mind. A person may not recognise a tropical Sun sign and still recognise this Moon. That is not mystery for its own sake. It is the difference between a public summary and an inner life.
Nakshatra is the Moon's mansion and its clock
The Moon moves about thirteen degrees a day, so the nakshatra usually changes within a day. There are twenty-seven lunar mansions.
The one the Moon occupied at birth describes a grain of mind, and it is the usual starting point for Vimshottari dasha. That is why a Vedic reading cares about the Moon in a way a magazine column does not. The mansion is used for timing, not only as a pretty name. If the birth time is wrong, the Moon may still be in the same sign while the nakshatra, and the dasha, have already moved.
Mother, home, and the mind that repeats
Classical Jyotish ties the Moon to mother, to the fourth house themes of home and inner land, and to the fluids and habits of the body.
A Moon under pressure can show a mind that does not rest, or a home that never quite holds. A supported Moon can show nourishment that is ordinary and reliable. None of that is a medical diagnosis. It is a way of seeing. When you ask about family, sleep, or how you take a period, the Moon in the sidereal kundli is part of the answer.
The Moon you were born with
You do not pick a Moon sign from a list. The sky at that minute decides, in the sidereal zodiac.
VedicAstrology.com calculates it from date, time, and place of birth. Then you ask. The main Moon article in the current library takes lagna, house, and dasha with this same graha.

