“The major part of the US military task in Vietnam can be completed by the end of 1965.” Robert McNamara, Secretary of Defense.
“You ain’t going nowhere, son. You ought to go back to driving a truck.” Grand Ole Opry manager Jim Denny while firing Elvis Presley in 1954.
“No woman in my time will be prime minister.” Margaret Thatcher, 1969.
“Transcontinental mails will be forwarded by means of pneumatic tubes.” Felix Oswald, on the future of communications, 1893.
“I don’t need bodyguards.” Jimmy Hoffa, 1975.
“Rod will stay with me forever.” Britt Ekland on husband Rod Stewart in 1976. Forever lasted a year.
“I want to be an old-fashioned lawyer, an honest lawyer who can’t be bought by crooks.” Richard Nixon, 1925.
“You will never amount to anything.” Teacher to ten-year-old Albert Einstein.
“No matter what happens, the US Navy is not going to be caught napping.” Frank Knox, Secretary of the Navy, December 4, 1941.
“Inventions reached their limit long ago and I see no hope for further development.” Julius Frontinus, 80 AD.
It would be easy to extend the list to thousands. There are so many more ways to be wrong than to be right that the odds are any expert opinion will be the former. It doesn't hurt to listen, but keep the salt-shaker within easy reach.