Intellectually inconceavable!
No beginning and no end ?
No way!
Why?
Because we know everything around us was born and will die.
It simply means that everything evolves one way or another.
It is irrationnal to understand that everything starts and ends except the universe. Why should the universe be an exception?
Maybe the universe didn't start with a big bang, but it did start, even if it started from another dimension or many more years before.