What did all those ancient Hindu/Buddhist/Taoist etc. sages mean with all that jazz about 'the self being an illusion'?

What if I were to say to you, "An inch is an illusion." Or perhaps better, "A line of latitude/longitude is an illusion."

You, like me, would probably nitpick a bit and say something like "well mental construct is a better description than illusion", and I would agree with you. Inches and lines of latitude/longitude are mental constructs superimposed on reality for the purpose of measuring it, but nowhere in nature can you go out and 'find an inch' or 'trip over a line of latitude' -- they do not 'exist' in nature in the same way that, say, a tree does.

The 'self’, 'ego', or 'I' (as western man conceives of it) is exactly the same kind of thing — a mental construct superimposed on reality for the purposes of measuring it. A next natural question is: what is the self designed to measure? As inches are to length and latitude/longitude are to position on our rock ball, what is the self related to?

I believe the 'self' we carry around is something the universe has manifested as a measurement device for which branch of the multiverse our collective reality should enter, in much the same way our body has manifested nerve endings and eyes etc. to measure various aspects of this universe and allow our physical organism to navigate it.

And now, some cool quotes:

"Talent hits a target no one else can hit; genius hits a target no one else can see."

-Arthur Schopenhauer

"Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on."

-Augustus De Morgan

"There was a young man who said though, it seems that I know that I know, what I would like to see is the I that knows me when I know that I know that I know."

-Alan Watts

"Every triangle is a love triangle when you love triangles."

-Pythagoras

"Heresy is not native to the world; it is but a contrivance. All things may be conjoined."

-Miriel

"So let us stop talking falsely now; the hour is getting late."

-Jimi