Do you believe this "garbage in , garbage out" saying is true?

It is always true for statistical analyses.

It is also true for political editorials.

It is true for computers and aviation for sure. GIGO.

And garbage trucks

I once heard this, “Don’t vote, it only encourages them”

What he says makes sense most of the time. And then there is a great leader who comes along and pulls you out of your cynicism.

The man was a genius.

The man was arrogant and cynical plagued with self doubt and unfortunately highly simplistic in his assessments like those he decried. This of course made him of course very popular with the same people and more inane and bitter as he got older.

I think “garbage” can often be filtered to extract desired substances. The old adage “garbage in, garbage out” is only sporadically relevant.

@Jibbah_Jabbah
We do recycle and oysters with pearls are found in the muck.

Since the price of gold has gone up so high, it has become cost effective to dredge up the ocean floor and sift through it, extracting trace metals, including gold.