Kasi,
’ I believe the Buddha interpreted these teachings (from live people, not from the Vedas) as ‘life is suffering.’
It has absolutely nothing to do with borrowed knowledge, what Gautama Buddha has seen was out of ones own direct insight into seeing things as they are. And if you have clear eyes, then you will be able to verify the same phenomenon - that life for most people who are living in a deep sleep is certainly full of suffering. By ’ suffering ‘, one does not mean being dragged and thrown into some kind of torture chamber. ’ Suffering’ simply means, that for one reason or another, you are simply not contented with things as they are. You may be trying to achieve all kinds of things in the world, but whatever is achieved is not going to be capable of providing anything more than temporary sastifaction. That is natural - the whole universe is in a constant state of change, the flux is unceasing. Not just the whole universe, but the mind and body themselves are also in a constant stream of change. So if you are clinging to anything which may arise in your experience rather than moving in harmony with the stream of things, then it is certain to create immense suffering for oneself. This is not a belief or a philosophy - this is simply direct insight into things as they are.
'The pre-Jain Sramanas were probably also an influence who introduced Reincarnation proper where all lifeforms literally take on other bodies with each birth (as apposed to dissolving into ‘elements’ that recombine). Sankara, the Hindu reformer, liked the later idea better ’
For one such as yourself, so called ‘reincarnation’ is just that - nothing more than an idea. But for one who has come to know oneself, through and through, it is simply a scientific fact. How ‘reincarnation’ is interpreted is another matter entirely, but it is not something which is born out of philosophy. Because once you enter into the deeper levels of your unconscious through meditation - then you will discover so many memories of so called past lives - not just memories of being a human, but there may be memories of being a bird, a dog, a lion, a fly or a worm - a whole history of life has been recorded in the depths of one uncosncious. There is certain information that has entered into ones mind which is just what your mind has gathered in this life, and there is certain information your mind has gathered at birth as a result of thousands of years of evolution, which is impersonal. And what is certain is that if your energies have taken the form of past lives, then they are certain to manifest in future lives. Nothing in existence is ever created or destroyed, it is just recycled in countless different ways. So while ‘reincarnation’ may be just an idea for those who have yet to come to such discoveries, for those who have been walking the path towards their awakening and have come to a certain direct experience of such things, it is simply a scientific phenomenon.