In Taoist Neidan (yoga or meditation) practice, an important concept is the "right moment" (活子時). In Zhao BiChen's Taoist Yoga, the author wrote, kids would giggle when they heard about this secret concept. Why would they giggle? And is there anything unseeming about this Taoist concept?
There has been some confusions in some literature on the meaning of "the right moment". The literal translation from Chinese is the "vivid moment of zi (子 first earthly branch)". The confusion arises from the the use of the character zi (子). Zi and other earthly branches have been used in many systems because of its mythical characters. For example zi when used in hour-system means the hours between 11:00pm and 1:00am; and zi when used in circular location system can mean the bottom point, the South of a map (or, to confuse things more, the North of I-Ching/five elements system!).
Some Taoists misunderstood its meaning and mistakenly consider the "right moment" as meditation between the hours of 11:00pm and 1:00 am. According to my research and practice, the right interpretation is to view zi as a location indication. In other words, the right or vivid moment happens at (I-Ching/five elements) North, right at one's perineum and surrounding pelvic floor muscles.
Some practitioners got it right up to here, but still can't proceed further. Why? Because in order to have the vivid feeling (that I shall explain later), one must first need to meditate to a stage in which one can control one's pelvic floor muscles with one's mind during meditative abdominal breathing.
If one can control the subtle movement of one's pelvic floor muscles, one can subtly move the control point to any focused area along the pelvic floor muscles. And when such focus rests on a practitioner's genital (applicable to both male and female), sexual energy will be subtly aroused, and such energy will seek a route to rush out. And here classic Taoist texts warned practitioners not to engage in erotic thought, but to direct and release such energy along the path of microcosmic circulation, along Du (督脈) and Ren (任脈). That is a famous Taoist saying: "A forward flow will breed a human, while a backward flow will breed an Immortal (順則成人，逆則成仙)".
You now know why kids will giggle!
PS: The release of sexual energy is also called sublimation of sexual energy. If such energy is not released (or sublimed), it will disturb the calm meditating mind of the practitioner. When such energy is sublimed, it can nurture the body and at the same time allow the practitioner to continue with his or her calm meditation. Hence, this is a natural method of seated chi-meditation.