It is said in the Manu-smriti that lust cannot be satisfied by any amount of sense enjoyment, just as fire is never extinguished by a constant supply of fuel. In the material world, the center of all activities is sex, and thus this material world is called maithunya-agara, or the shackles of sex life. In the ordinary prison house, criminals are kept within bars; similarly, the criminals who are disobedient to the laws of the Lord are shackled by sex life. Advancement of material civilization on the basis of sense gratification means increasing the duration of the material existence of a living entity. Therefore, this lust is the symbol of ignorance by which the living entity is kept within the material world. While one enjoys sense gratification, it may be that there is some feeling of happiness, but actually that so-called feeling of happiness is the ultimate enemy of the sense enjoyer
A conditioned soul tries to enjoy material happiness again and again. Thus he chews the chewed. But sometimes, in the course of such enjoyment, he becomes relieved from material entanglement by association with a great soul. In other words, a conditioned soul is always engaged in some type of sense gratification, but when he understands by good association that it is only a repetition of the same thing, and he is awakened to his real Krishna consciousness, he is sometimes relieved from such repetitive so-called happiness.
The twigs of the tree are considered to be the sense objects. By development of the different modes of nature we develop different senses, and by the senses we enjoy different varieties of sense objects. The tips of the branches are the senses — the ears, nose, eyes, etc. — which are attached to the enjoyment of different sense objects. The twigs are sound, form, touch, and so on — the sense objects. The subsidiary roots are attachments and aversions, which are byproducts of different varieties of suffering and sense enjoyment. The tendencies toward piety and impiety are considered to develop from these secondary roots, which spread in all directions. The real root is from Brahmaloka, and the other roots are in the human planetary systems. After one enjoys the results of virtuous activities in the upper planetary systems, he comes down to this earth and renews his karma, or fruitive activities for promotion. This planet of human beings is considered the field of activities