Something to shake the very foundation of your lack of faith

[Angrboda]

Mangal Singh was interviewed in March, 1983, when he was 79 years old. He described his near-death experience, which occurred approximately 5 or 6 years earlier. Unlike most subjects who have near-death experiences, he was not ill at the time, or did not consider himself to be so. . . . In response to questions, Mangal said he thought he might have been sleeping at the time of the experience, but he was not sure of this.

Near-Death Experiences and Hinduism

The International Association for Near-Death Studies sent out a questionnaire in 1992 inquiring about those who considered themselves to be near-death experiencers.  How close had they been to physical death when their episode occurred? ... 37 percent had theirs in a setting unrelated to anything that could be construed as life threatening. ... The 37 percenters claimed to have experiences every bit as real, involved, and life-changing as those that happened to people during death or close-brush-with-death crises; and their reports duplicate or parallel the same spread of scenario types and a pattern of psychological and physiological aftereffects.

— P.M.H. Atwater, The Big Book of Near-Death Experiences