Jimmy Carter Gives Advice to Trump, Then Talks Peanut Butter

Jimmy Carter's got some pretty simple tips for very-soon-to-be President Donald Trump ... but it's definitely easier said than done.

We got the 39th President of the U.S. at the Reagan Airport making his way to the inauguration festivities, and along with some advice for Trump ... he extends a pretty sweet invitation to President Obama for his retirement days.

But, all of that pales in comparison to Carter's passion for peanut butter -- the former prez dishes on how to properly chow down on PB. Hint ... there's more to work with than jelly.