A Summary of the Srimad Bhagavatham : Ch-5. Part-3.
5: Narada Instructs Yudhisthira on Ashrama Dharma :
But anyone who is interested in the welfare of their own being, and knows what is good for them, has to remember that the pleasant is not always the good. We always like pleasant things, sweet things, and they attract our senses perpetually, so that the senses gather our energies and pour them outwards on the conditions of life outside; and if this is the habit that we form right from the beginning of life,
we will have to reap the fruit of this misbehaviour towards the end of our life. It is not necessary that we must be bedridden in old age. That condition is imposed on us by the circumstances into which we are born and which we have introduced into our own selves by the desire for dissipation.
We feel a great joy when we pour ourselves externally in love for power, in love for money, in love for enjoyments of various kinds, not knowing that this is not real pleasure because when the tension that is created in us—when the quantum of energy already existing in us—wells up like an elephant’s energy, it does not know what to do.
Either it will go vertically or it will go horizontally. Like a river in flood, it can move in any direction. It is necessary that we should prepare a program of our life by which our energy quantum rises vertically, and does not move horizontally. Otherwise, it will be like a dissipated river flooding everywhere and destroying villages and persons.
The vertical ascent of energy is the art of the Brahmacharya system. The energy rises gradually through the lower parts of the body to the upper part until the brain becomes brilliant, sharp, and able to catch everything very quickly.