Definition
Refers to something that one has never experienced or seen before in their lifetime, often used for emphasis.
有生以来
I have never heard such a ridiculous excuse in all my born days.
在我这一生中，我从未听过如此荒谬的借口。
I have never seen such a beautiful sunset in all my days.
在我这一生中，我从未见过如此美丽的日落。
In all my born days, I've never met anyone as unreasonable as him.
在我这一生中，我从未见过像他这样不讲理的人。