That is not correct, ShivaFan. The practice is very old and finds mention in Greek, Zoroastrian, and Indian mythology and scriptures. It existed before the Greeks (Western Aryan branch) separated from the Iranians and Indians (Eastern Indo-Iranian Aryan branch), approximately around 3,000 BC according to one view. That was when the sun rose in the asterism of Orion on the day of vernal equinox. Quote from B.G. Tilak's book, "Orion", here:
"In the Greek mythology Orion, after his death as above described, was placed among stars, where he appears as a giant with a girdle, sword, a lion's skin, and a club. Now, if as remarked by Plutarch, Orion is an original Greek name, we should find some traces of these various adjuncts of Orion or at least some of them in the old Iranian and Indian works.
I think we do, only if we look for them with a little more attention and care, for the transformation is more specific and peculiarly out of the way in this case. In the Vedic works Soma is said to be the presiding deity of the asterism of Mrigashiras. Soma is Haoma with the Zoroastrians. The 26th verse in the Haoma Yasht is as follows: “Fra te Mazdao barat paitrvanim aivydonghanem steher-paesanghem mainyu-tdstem vanghuhim-daendm Mdzdayasnim”, which has been thus rendered by Mr. Mills in his translation of the Zend Avesta, Part III., in the Sacred Books of the East Series (p. 238): “Forth has Mazda borne to thee, the star-bespangled girdle, the spirit-made, the ancient one.”
I have before pointed out that Orion or Mrigashiras is called Prajapati in the Vedic works, otherwise called Yajna. A belt or girdle or a piece of cloth round the waist of Orion or Yajna will therefore be naturally named after him as yajnopavita, the upavita or the cloth of Yajna. The term, however, now denotes the sacred thread of the Brahmans, and it may naturally be asked whether it owes its character.
The mantra is not to be found in any of the existing Sanhitas, but is given in the Brahmopanishad and by Baudhayana. This verse is strikingly similar to the verse quoted above from the Haoma Yasht, It says, "Yajnopavita is high and sacred; it was born with Prajapati, of old.”
“Yajnopavitam paramam pavitram, prajapatyeryat sahajam purastat.”