What does this quote mean? "A failure is a man who has blundered, but is not able to cash in on the experience." - Elbert Hubbard?

most people learn, if they do at all, from their own failed experiments. The universal pattern is try, fail, correct, and try again -- recycling as needed.  The quote refers to people who either do not correct after a failure or cease trying after N attempts. they have failed the test situation -- often permanently.  My lifelong experience [I'm 69 and retired] is that very, very few people actually learn from the failure experiences of others -- usually, we think of these few as geniuses ... when what they actually do is look at other's failures [or successes] and learn from them.  Example: The typical 19 year old non-college graduate from school in Germany has a full time job at full time, adult wages. This has been the norm in Germany for 40 or more years. America, as a collective nation, seems unable to learn from the German success in this how to restructure our society so that 16 to 19 year olds have this opportunity. We've had unsuccessful systems in our inner cities in this area for at least 50 or 60 years -- and we continue to fail to learn from those unsuccessful outcomes. Of course, maybe the problem is institutional racism [since inner city schools are heavily minority in student membership], or maybe the problem is structural impediments from the entrenched teacher's unions whose members benefit from the guaranteed jobs and retirement packages at taxpayer expense. America does not have and has not had any Presidential candidate in at least 50 years who apparently gave a rat's Axx about this.  ["just add more money" has been tried for 50 years and continues to fail as a policy prescription.]

There is an old saying: "The person who never made mistakes never made anything."  It means almost the same thing as the quotation from Hubbard.