I've seen my friends who are Brahmin(Hindu sub-caste) wearing a janoi (Gujarati for "sacred thread").
Also, when they go to the washroom, they wear that thread on their ears.
Why do they wear that thread?
Found answer after googling it's been quite a long story but i have to write to explain others who have the same question
Earlier a few centuries back. Men would not wear shirts, they had their top body open, so to identify -
When a person wears a single (1 set of 3 ) it means he is a brahmin (unmarried) When a person wears a double(2 set of 3 ) it means he is a brahmin (married) When a person wears a treble (3 set of 3 ) it means he is a brahmin (married) but not without father.
White is peace,knowledge etc. There is no show off, it is the duty they are to perform with respect to the above number of thread sets.
Three thread in a set is GOD G-Generater O- Organiser D - Destroyer which in local parlance is Brahma Vishnu Mahesh
Some one says
It is only a symbol for peace. Actually it should be wear around the mind
One blog explains me very well
The Janehu/Upanayanam ceremony is a very important tradition among the Brahmins. After the Namkaran (naming) ceremony, it is probably the next biggest occasion for the Brahmin boy. This ceremony marks the boy's entry into studies.
The Upanayanam ceremony takes place when the boy is around 7-8 years old. A sacred thread, called Yagnopavitam is placed around the left shouder of the boy. This thread is a composite of 3 threads, signifying Goddesses Gayatri (thought), Saraswati (word) and Savitri (deed) respectively. There is also a knot in the middle that signifies the unending Brahman. A head priest whispers the Gayatri Mantra into the boy's ears, and he is formally initiated into education.
After this, the boy is supposed to tie the thread around his ear whenever he passes urine, so as to avoid getting it into contact with the excretory organs and thus getting contaminated. The thread is also changed once a year on the occasion of Shravani Purnima, the full moon day in the month of Shravan. This is also known as Avaani Avittam in Tamil, and coincides with the Raksha Bandhan or Rakhi festival of North India.
The below photo shows Brahmins taking part in the thread changing ceremony.
Well, so much so for the religious part of it. But what is the factual meaning behind this Janehu/Upanayanam ceremony? Let us explore.
Though the fact about keeping the thread pure by avoiding contact with the excretory organs is understandable, there is a hidden meaning in this practice.
It is a scientifically proven fact that a vein passing through the ear regulates the flow of urine. Therefore, when the boy wears the sacred thread around his ear while passing urine, he is unconciously helping his urinary system to regulate the urine flow, thus keeping his urinary system, bladder, etc. healthy and free of problems.
Further, we should take into account the fact that the Brahmins of olden days did not lead a very active lifestyle (i.e.) they were mostly conducting Pujas, where their primary role was to be seated and chant Mantras. In this scenario, it would have been difficult to keep their kidneys in top-shape. This is why this alternative system of Yagnopavitam (sacred thread) has been formulated.
I don't about other things but this act of tying the thread around the ear is sheer ignorance. In earlier days, men used to defecate in the open by squatting. The thread was tied around the ear to prevent it from touching the ground and getting contaminated. Today's generation tie the thread around their ear even when they are using western urinal in an act of mindless ritual. NO, there is no vein near the ears that help in regulating the flow of urine. Its a lie to support this mindless act.