There are both essential and non-essential elements in the life of a monk. The vows: obedience to rule and abbot, conversion of life (celibacy and poverty), and stability (the commitment to remain in one’s monastery and community for life) are essential, the core of his way to God. There are also practices, known as observances, which are not vowed, which contain some of the most distinctive and important aspects of monastic life, as well as some that are far less important.
Some of the less important practices, which can change with cultural and historical circumstances, are the distinctive clothing monks wear, haircuts, liturgical celebrations, etc. These can change and frequently have over the centuries and yet they don’t change the essential nature of monastic life.
Other observances are at the very heart of what it is to be a monk and would include: withdrawal from society (living an enclosed life), the practice of silence, the life of prayer, fasting and vigils, and monastic work (the Cistercians emphasize manual work). Without these, monastic life would be nothing more than a comfortable club; with them the monk takes on the means for his vow of conversion of life, living it in earnest each day as he seeks to know himself and God.
It’s worth thinking about - that some people freely take on such practices for purposes unrelated to personal gain as understood within our culture. There are men and women throughout the world that rise every day of their life long before the sun shines to chant prayers to the unseen God they pledge their lives to, take simple meals in silence, and spend solitary hours each day in sacred reading and meditation. And there are no vacations from this life of devotion.
These practices are the tools monastic life has always employed to guide the traveler on his way to the one essential thing: love. For the ones who take on these disciplines with a true heart, and as St. Benedict puts it “run on the path of God’s commandments” (Prologue vs.49 ) the reward is what we all are seeking - a love that surpasses all understanding.