Once you have an upanayanam ceremony, you wear sacred thread every day as a marker of your intellectual birth.
One of the core values of the Hindu community is learning. The upanayanam is the community's way of celebrating the beginning of your journey to intellectual growth. While this growth historically was limited to the in-depth study of the Hindu religion, many Hindus today have an upanayanam ceremony but choose to study fields other than Hinduism.
Another concept behind the upanayanam ceremony is the idea of brahmacharya, which is one of the four life stages outlined in Hinduism on the path to spiritual liberation from the cycle of life and death. Starting from the upanayanam ceremony up to when the person turns 25 years old, they are in the stage of brahmacharya, which emphasizes education.
This tradition connects to its environment in many ways.
Firstly is the material of the thread. The sacred thread is composed of three intertwined groups of nine cotton strands. In Tamil Nadu, where I attended an upanayanam, the three strands represent the goddesses Parvati (energy and love), Sarasvati (knowledge and education) and Lakshmi (wealth and good fortune). In ancient times, people would wear a piece of clothing instead of a thread. However, it evolved into a sacred thread because a thread is more manageable and convenient to wear under modern-day clothing. India is one of the world's largest cotton producers, so it makes sense why the sacred thread would be made out of cotton.
