Story highlights Warren Buffett is one of the richest men in the world

During an interview he offered opinions on Obamacare and the government shutdown

He also gave a peek at what is in his wallet: a wad of $100 bills

No smartphone for Sage of Omaha; he uses an old flip cell phone

He played the ukelele, weighed in on the Obamacare debacle and even flashed his prehistoric flip cell phone.

Suffice it to say, we got to see another side of Warren Buffett during an interview with Piers Morgan Tuesday night.

Accompanied by his son and grandson, the billionaire investor gave his unique take on almost everything.

And with that, he let Morgan and American take a quick peek in his wallet. Literally.

Here are some of the highlights.

JUST WATCHED Warren Buffett plays ukulele for Piers Replay More Videos ... MUST WATCH Warren Buffett plays ukulele for Piers 01:37

JUST WATCHED Buffett: I've only sent one e-mail Replay More Videos ... MUST WATCH Buffett: I've only sent one e-mail 03:03

JUST WATCHED Warren Buffett on power of a handshake Replay More Videos ... MUST WATCH Warren Buffett on power of a handshake 04:00

JUST WATCHED Warren Buffett: We can't play games Replay More Videos ... MUST WATCH Warren Buffett: We can't play games 02:38

On Obamacare and Kathleen Sebelius

Buffett has in the past supported President Barack Obama. And it seems that this support extends to embattled U.S. Secretary of Health and Human Services Kathleen Sebelius. Buffett says give Sebelius some time to fix the Obamacare mess she is overseeing.

"I am a friend of Kathleen's. And I'm a friend of her when she's in trouble. I like Kathleen. I feel sorry for her in the position she's in. Obviously, it's a huge screw up but it will get worked out, " Warren Buffet told Piers Morgan.

On technology

Can you tell a lot about the wealth of a man from his cell phone? Apparently not when it comes to the 83-year-old financial guru.

"This is the one Alexander Graham Bell gave me," joked Buffett, as he revealed a Nokia flip phone, a relic compared to today's smartphones. "I don't throw anything away until I've had it 20 or 25 years."

By the way, Buffett's son, Howard Graham Buffett, did not bring a phone to the interview.

And grandson Howard Warren Buffett led the three generations when it came to technology. He had two Blackberries.

Buffett's standoffish approach to technology extends to e-mail.

"I sent one e-mail in my life," revealed Warren Buffett. "I sent it to Jeff Raikes at Microsoft and it ended up in court in Minneapolis, so I am one for one."

On his biggest mistake

When you are one of the richest people in the world, it is hard to say you made many mistakes. Buffett listed one.

"I bought a company in the mid-90s called Dexter Shoe and paid $400 million for it," Buffett said. "And it went to zero. And I gave about $400 million worth of Berkshire stock, which is probably now worth $400 billion. But I've made lots of dumb decisions. That's part of the game."

On his wallet

Buffett says he has been carrying the same wallet for 20 years. And when Morgan asked Buffett to show America what is inside, he obliged.

He whipped out the black wallet for a split second. If you blinked you missed it. The highlights: A family picture. A wad of hundreds. And an American Express card from 1964.

"It goes with the cell phone," Buffett joked about the almost 50-year-old credit card.

On the shutdown showdown

At least one part of the recent battle between Democrats and Republicans that caused a 16-day government shutdown should never happen again, Buffett says. The battle should not take place around whether to raise the debt ceiling limit, he said.

It could be catastrophic to the economy.

"I think that both parties should declare the debt limit as a political weapon of mass destruction which can't be used," he said. "I mean, it is silly to have a country that has 237 years building up its reputation and then have people threaten to tear it down because they're not getting some other matter."

On investment

Who wouldn't ask the "Oracle of Omaha," who made his fortune investing, for a stock tip? Fans watching the interview needled Morgan via Twitter to ask the Nebraska billionaire how he would invest $1,000 right now.

Buffett's answer: "Well you asked," he coyly told Morgan. "You've done your job."

It seems investment advice doesn't come easy.

"I can't even get an answer to that question," Howard Graham Buffett joked.