Like you, I used to think of death as the same as the non-life before I was born.
But, we can only remember back as far as age 3 or so. We can't remember suckling. We can't remember the birth process. This doesn't mean that we we weren't alive when we were 12 months old, it merely means that our memory doesn't go that far back.
Some claim that reincarnation is possible (Edgar Cayce, for example). Cayce had been a devout Christian, then got weird visions of future and past events. Cayce really didn't want to believe this things, yet many of the things that he saw came true. Cayce didn't want to believe in extraterrestrial aliens, nor Atlantis, etc. Some people claim to remember past lives (though it is odd that they were all powerful kings....seems like a psychological issue instead....not insanity, but a trick of the mind).
Cayce's description of the location of Atlantis was around the Bahamas. Yet, ancient texts (Plini the Elder, as quoted by Plato, places Atlantis beyond the horns of Gibraltar (Hercules), on a round land mass that sunk. Such a land mass does exist (called the Azores), and it is located on the ever-spreading mid-Atlantic Ridge, just as Iceland is.
Presumably, suicide might prevent ascension to heaven. So, one must live a good life, atone for sins, and only then may one ascend to heaven.