We have just understood that happiness is found within, and not without, meaning the search for it has to turn inwards. So sadhana is all about the search within; it is a journey from extroversion to introversion.
Believe me, this doesn’t mean that a sadhak (one who does sadhana) neglects the world or takes a cowardly flight from it. One has only turned inwards in order to find the truth, which is one’s own self.
This search for one’s true identity or consciousness, also the search for true happiness, is not just reserved for renunciants, monks or sanyasis. Every human being, without distinction, can embark upon this search–people like you and me who live in this world, who work for one’s living, has a family and who cares for other human beings.
The daily activities, the day-to-day travails are often distracting in this inner pursuit. So distracting, that in order to do sadhana, one has to find the appropriate time to sit in solitude and practice. Once one becomes an expert at this, sadhana can be done anywhere in the world.
This practice of sadhana is generally called meditation. This meditation is not some kind of mumbo jumbo to be practiced behind closed doors. It is merely a method passed onto a student by a spiritual teacher, who has practised it himself and has customised it–according to the nature of the student–before transmitting it.
Once one becomes an expert at this, sadhana can be done anywhere in the world.