SN 12.20 Paccaya Sutta: Requisite Conditions
The Buddha teaches Dependent Origination and adds that someone who has understood it would not run back into the past thinking:
“Did I exist in the past?
Did I not exist in the past?
What was I in the past?
How was I in the past?
Having been what, what did I become in the past?”
That person would not run off to the future with similar questions.
They would not become confused about the present asking:
“Do I exist?
Do I not exist?
What am I?
How am I?
This being - where has it come from and where will it go?”