Today is the purnima (full moon). It is the best time for spirituality and worst time for party, the worship of Guru (teacher) is on that day as this full Moon represents the Jupiter, archetype of the wisdom and upadesha (instruction).
Jupiter together with Sun and Moon represents the satva guna which is the highest among the three material forces ruling this world. Bhagavad Gita (and Bhagavatam Purana) says that satva consists of (true) happiness and knowledge and in Jyotisa (astrology) Jupiter rules both of these things. Jupiter exalts in the forth house of inner happiness and is karaka (significator) for the fifth house of apara-vidya knowledge (and vedanga) and ninth house of para-vidya (spiritual or vedanta).
Jupiter represents the inner happiness, which comes from within, as Gita says that the happiness in the mode of satva is first bitter and then sweet. The bitter part is the sadhana (practice) or the tapasya (austerity) in order to win śreya over preya (long term happiness overy short term happiness). There is famous research done by psychologists in which children striving for śreya (delayed satisfaction) from early age attained much more in adult life. Among the three types of responding to stimuli introverts also tend to favour more śreya (sacrificing short term happiness for more fulfilling and longer happiness type) then preya.
Jupiter is also the natural lord of 12th house of dhyana (meditation) although the karaka of meditation is headless Ketu. Headless because meditation should raise one above the mental level, therefore also the wavering Mercury feels debilitated in the house of Pisces (dhyana and moksa – meditation and liberation).
To transform vidya into (vi-)jnana (knowledge to realization) the sinus waves of the mind must have very broad radius or in other words the ocean has to be peaceful, then one can go deeper and easier catch the connections, digest and transform them into essence of wisdom. David Lynch nicely summed it up: “Ideas are like fish. If you want to catch little fish, you can stay in the shallow water. But if you want to catch the big fish, you’ve got to go deeper. Down deep, the fish are more powerful and more pure.They’re huge and abstract. And they’re very beautiful.”
So to reach these level of peaceful mind-waves, the mind has to decrease the rajas guna in life as the rajas (external enjoyments) make the mind wavering and therefore block the śanti (peace) and consequently the jnana (realization) coming from mix of learning and contemplation. So the brahmanas (spiritual class) in ancient ages were inspired to practice lifestyle in satva guna from an early age.
Dhyana (meditation) being of Jupiterian quality puts the broken pieces of ourselves together. This broken pieces are the vayu or vata (air) and are further disintegrated by things like alcohol (being the vata ingredient represented by Saturn), drugs and other things in tamas (guna of ignorance). This takes one further away from the inner (true) happiness and light. Dhyana puts those broken things together and heals us from within.
The soul normally needs that dhyana-happiness all the time. Therefore Bhaktivinod Thakur said in Jaiva Dharma that sadhaka (aspirant) needs 3 “meals” daily (for him, one “meal” was 64 rounds of mantra). If one doesn’t get the inner ‘meal’ coming from the touch of brahman (spiritual inner light) from upasana (spiritual practice be it meditation, japa mantra, kirtana and so on) then one must rely on the other types of happiness (there is no compromise in this).
Jiva (soul) according to the Vedas is of sat-cit-ananda rupa (form), is full of happiness and all the time demands that happiness, or rather want from one to take the shees of ignorance away to shine through. If we don’t give the soul the happiness from upasana then we need to provide the love, as the love is the direct reflection of that.
The love however is dependent on our and partner’s karma, so it is the mix of satva and rajas now (mode of goodness and passion), we are on the border, the things are less secure, so also less shanti (peace) is there, but still the satva guna prevails (being highest In love of mother to the child).
If there is no love with the trait of Venus (self-sactifice) then the satva is even less and one is thrown to the rajas force (sensuality) and the soul demand for happiness is filtered through lower means like sensuality in the form of sex, drugs and other unstable sensual pleasures.
If even this requirment is not met then the tamas prevails where one gets the satisfaction without the presence of the other person (upanisads call this anna-maya) and this covers fully the souls-knowledge and one lives in ignorance like an animal (http://www.bhagavad-gita.org/Gita/verse-16-11.html).
As the higher the waves the lesser the knowledge, or rather the drishti (vision) is totally lost in tamas (ignorance) and is fully powerful in satva. One need protect this type of awarness to maintain the inner peace, happiness, fulfilment and knowledge which is the only thing which goes with soul from birth to birth.
This can also be one of the reason to live drug-free/straight edge.