I was unknowingly trained in (Rinzai?) Zen practices (no theory) by my Sen-Sei as part of my martial arts training. I didn't realize this until years later. *doh!* Classic!
Unknowingly trained... that's interesting. What was it you found yourself trained in that you weren't being aware that you were being trained in?
Personally, I don't believe very many, if any aspects of Hinduism have outlived purpose. The Kumbh Mela celebrates an astrologically significant time. The person whom I knew who went, went from Mauritius, walked the 10 miles in, did his dip, and exited on the same day. That kind of sacrifice and commitment builds will. There has to be a massive sannidhya to the crowd itself.
Refresh my memory on some of the things done/seen on the Kumbh Mela. You say it celebrates an astrologically significant time; what is the event that it celebrates?