What I believe in is reincarnation. People are born again and again to pay off their karmic debts. It's a long story but it seems to be the most outstanding explanation out there, especially if you read about all the near death experiences. I am reading a book right now based on true experiences and it's called Journey of Souls by Dr. Michael Newton. Very eye opening so far.
Mozart, for example, was able to compose at age 5 and yet none of his parents, gran-parents were musicians. Nor was he exposed to that kind of musical environment at an very early age, so he clearly knew a lot of the stuff already when he was born. Einstein had no renown physicist in his entire generation and yet, he took the world by storm in the science world. There are countless numbers of examples out there that show that there might just be something out there we are overlooking.
A lot of people are actually discovering a lot of stuff through hypnosis lately. A person I know was extremely afraid of the water and she had found out recently that she was drowned in her previous life and that fear stayed with her in this life as well. Of course her fear went away once explored. There's an incredible book out there called Many Lives Many Masters by Dr. Brian Weiss. And of course there's that very famous book called Life After Life by Dr. Raymond Moody that changed the history of human race in a very interesting way. All worth reading if one is really interested to find out the truth.
So what I am saying is that, the life we have is the life we chose deliberately when we were in between lives but since we have free-will, we often lose track of things once born. Because it's so easy to forget once you enter this life, where you are conditioned to forget all your past lives as otherwise you wouldn't learn your lessons if known. It's a very hard concept to digest of course, especially if you tell someone who's born with a condition that he or she chose it deliberately to experience it in this life. But through constant struggle and suffering he'll learn the valuable lessons. I suppose he wasn't learning it otherwise when he had a choice but now he has left himself no other choice but to learn it.
But of course people believe in different things but I tend to look at what's going on in our life and what life in general tells us. That's why all our experiences are quite valuable because they are always telling us something.