Saraswati is the goddess of knowledge and wisdom. Many sanscrit scholars and teachers take her name as part of their names.
I chose that name a couple of years ago when I was interested in the knowledge and wisdom without sexuality aspects. It really caught my attention that she could be the goddess of marital arts and asexual herself. I feel like I have both sexuality and asexuality going on in me at the same time. What fun!
The most important factor in my choice is the following. I was starting to do Sanscrit mantra; an hour or more a day.
Mantra is considered 'sacred speech'. Saraswati, as the goddess of speech in the primordial sense, represents a root to understanding of spiritual, material, and personal power through speech. Saraswati is that principle which, in Christianity, is referred to as "In the beginning was the Word." At its core mantra is magical speech and is ruled by the Saraswati principle. Saraswati is referred to as the 'essence of the Vedas' and the essence of the great Gayatri mantra for spiritual illumination (this is the one I do for an hour or more a day). She has other names in the Vedas.
. Eloquence
. Transcendental knowledge
. Speech in every aspect
. Nobel one
. Power of immense being
. Seed of the Word
In the RigVeda there is a quotation from Saraswati as follows:
" I Saraswati, as Divine Speech, make those whom I love formidable, one a Brahim, one a Rishi, another a sage. By the power of mantra they follow my path of divine speech and I enter into them."
So this is the complete answer to why I choose my screen name and also why so many sages and teachers append her name to theirs.
Devi just means goddess. And in Sanscrit sometimes a word or thought is repeated for emphasis.
Hope I haven't bored anyone to death with my explanation.
