For various excellent reasons (explained elsewhere in the issues of Back to Godhead), we accept that the book known as the Bhagavad-gita conveys the words of Krishna Himself. So the members of the Hare Krishna movement, like devotees of Krishna for thousands of years, learn about reincarnation from the words of the Bhagavad-gita.
In the Bhagavad-gita Krishna tells us that reincarnation happens to everyone. “For one who is born,” Krishna says, “death is certain. And after death one is sure to be born again.”
Krishna compares this journey through a succession of lives to the changing of clothing. Your true self—your “soul”—is eternal, but it goes through temporary bodies, one after another.
So it’s not that you “become a different person” when you change from one body to the next, any more than you become somebody else when you change your clothes or when you grow from a child to an adult. You’re always the same you, but you watch your body and mind transform from those of a child to those of a youth and then those of an old man or woman. Similarly, Krishna says, death is but a transformation from one body to the next.
Still, death is like nothing else under the sun. It’s the biggest jolt there is. And when we get to the other side, we forget all about what we were doing in the life before, just as a person who falls asleep forgets what he was doing during the day and then wakes up and forgets about his dreams.