To have a clean brain is good because keeping it dirty is uncomfortable both for us and for others. We have the experience of how, when our mind is irritated, this makes it hard for us and our friends, colleagues, and relatives.
There are two levels of cleanliness – physical and mental. We take daily showers to keep our gross body clean. We also need regular mental showers to keep our mind clean.
Pure state of mind means that we posses virtues such as humility, nonviolence, tolerance, simplicity, cleanliness, self-control, detachment, and constant and unalloyed devotion to God.
Impure state of mind means that we are engrossed in low qualities like envy, pride, anger, lust, greed, madness and illusion.
The best way to keep our brain clean is to be in contact with God. He is supremely pure. There cannot be any adulteration in the presence of God; therefore, if He is always with us we will always be uncontaminated. Another quality of God is that He is antiseptic, meaning that if we are connected to Him He will protect us from all types of future contamination, just as a strong immune system protects the body from infection.
How to contact God? There are some very effective methods to accomplish this:
One easy and practical way is by chanting mantras which consist of different names of God. Since God is identical with His names, if we chant these mantras we are in direct contact with Him. In the Vedas it is said that the best of all mantras is the Hare Krishna Maha-mantra (Hare Krishna Hare Krishna Krishna Krishna Hare Hare, Hare Rama Hare Rama Rama Rama Hare Hare).
Another way is through reading spiritual books such as the “Bhagavad-gita as it is” or “Srimad-Bhagavatam”. These are the words of God and His dear devotees. They provide spiritual knowledge which will protect us from contamination.
It is also helpful to keep friends with saintly persons. Birds of a feather flock together. By associating with pure-hearted people we become pure like them. Saintly persons are all those whose prime objective in life is to serve God (Krishna). They can teach us many practical tips of how to keep our brain clean. They can also answer our questions. Attempting to attain purity in our modern life can be a complicated affair and those good-hearted people can help us to do so. For example, giving up bad habits like drugs, smoking, or drinking may be hard, but if we have good company it will be easier.
Eating only vegetarian, spiritual food is another prerequisite for purity. Food is one of the major agents for both contamination and purification of our brain. If we eat impure food, prepared by people with impure consciousness, we will be contaminated. If we eat pure food that has been prepared by persons in pure consciousness we will be purified. The same applies to music and other arts. The mood of the composer permeates his tune and affects the consciousness of the listener.
Besides preparing the food in pure consciousness and with proper ingredients (this precludes meat and other impure products obtained by violence) it is also important that the food is first offered to God with love and devotion. Only in this case it will be free of contamination and will have a purifying effect.
Another important factor is regulation of our daily routine. By keeping a regulated schedule, we can mitigate all impurities in the body and the mind. Regulation means for example going to sleep and waking up at the same time (preferably, as early as possible), eating at a regulated time, keeping a regular program for physical and mental purification (exercise and mantra meditation), etc.
There are also some inherently impure activities which we should avoid since they will only aggravate our already existing contaminations. Eating meat, gambling, taking intoxication, and having non-regulated sex should be shunned as much as possible. Abstaining from these harmful activities will become easier in time, especially when we develop а more refined taste for higher spiritual activities.