I spend half my life forgiving myself for things I did, and the other half of my life forgiving myself for things I wanted to do and didn't.
Know Thyself’ was written on the forecourt of the Temple of Apollo at Delphi.
From Shakespeare's Hamlet Polonius says: "This above all: to thine own self be true, And it must follow, as the night the day, Thou canst not then be false to any man."
Psychology tells us that we first have to discover that we exist...'I am'...thereafter we can pose the 'who, what, where and why' I am, questions.
The comparison of East and West philosophies didn't really get any serious consideration until the late 19th century. Even then it took much effort on the part of the Theosophical Society to find the parallels, often seen as paradoxes, with the existentialist traditions of Buddhist thought. Refined, by such writers and investigators as Erich Fromm and Alan Watts, and others, the marriage between East and West began a long and arduous understanding that began to appear in 20th century literature. The quest to define the riddle of existence was exposed for anyone who wanted to examine it.
It isn't that there weren't other influences on both East and West, and also on each other, it was just that it all seemed to have gained a greater understanding which began during and after the Enlightenment with its many humanitarian reforms.
In authoritarian cultures, religions have imposed faith in their deities as being an answer, to the great riddle of life, that non-believers do not accept owing to a lack of scientifically verifiable evidence.