Scientist have found data that NMN found in avocado and a few other substances can reverse aging
It is said that in the initiation of yoga, a guru can give a fountain of the Amrita to the disciple. Such experiences are needed for a disciple to have unshakable faith.
There are many such things a guru can do – depending on what is best for disciple
Oh ignorance ( books ) what can you give ?
Bhavin