“Only the paranoid survive.” – Andy Grove, former CEO of Intel

A funny quote, yet very true, especially in the tech industry, where advancement is very fast, competition tough.
Andy Grove, former CEO of Intel, was credited with being the driving force behind the huge success of the semiconductor computer circuit manufacturer Intel Corporation. He served as Intel’s president (1979–97), CEO (1987–98), and chairman (1997–2005).

“Only the paranoid survive.”

– Andy Grove

My Opinion:
In some sectors, like tech and startups, where you have tough competition and high reliance on the workforce, you need to be paranoid.
If you read quotes by famous tech innovators or CEO like Steve Jobs or Bill Gates, you will notice that this fear of being out-competed is always there, even after building multi-billion companies. And that is in part due to the dynamics of information technology business style. Tech bubbles, have already decimated thousands of billion dollar companies, tough competition and corporate espionage theft & sabotage have done similarly.
The quote, thus will not apply to 90% of normal none IT related businesses, but would definitely apply to a huge % of tech, startups and IT businesses.