The Biden family may have been wondering what Joe Biden was doing in a MAGA hat Wednesday afternoon.

The bizarre scene unfolded at a firehouse in Shanksville, Pennsylvania - where United Flight 93 crashed 23 years ago - as Biden was honoring the anniversary of 9/11.

Biden wears MAGA hat

Biden had exchanged some banter with a Trump supporter in the crowd who asked the "old fart" for an autographed hat with the presidential seal.

Then Biden said, "I need that hat," pointing to the man's Trump hat.

With a plastic grin, Biden placed the hat on top of his head as the crowd roared.

"I'm proud of you now, you old fart," the Trump supporter quipped.

Biden then said, "Remember, no eating dogs and cats!" a reference to rumors of migrants eating pets in Springfield, Ohio.

It was a surreal and wholesome display from a president who spent almost four years shouting about a "threat to democracy" from Trump and his MAGA movement.

Indeed, many found it so unbelievable, they speculated Biden was demonstrating more of the cognitive decline that led to the sudden end of his political career over the summer.

Gesture of 'unity'

Others saw Biden's surprising gesture as a spiteful message to Kamala Harris, who took Biden's place at the top of the Democratic ticket in July.

Hours before Biden put the hat on, Donald Trump offered to give Harris her own MAGA hat during their presidential debate, citing her recent shift toward the political center.

"She’s going to my philosophy now. In fact, I was going to send her a MAGA hat,” Trump said.

The next day, Trump, Biden, and Harris appeared together in New York City to honor of the victims of 9/11.

The White House said Biden wore the Trump hat to show goodwill on the 23rd anniversary of one of America's darkest days.

"At the Shanksville Fire Station, President Joe Biden spoke about the country's bipartisan unity after 9/11 and said we needed to get back to that," White House spokesperson Andrew Bates posted to X.

"As a gesture, he gave a hat to a Trump supporter who then said that in the same spirit, POTUS should put on his Trump cap."

"He briefly wore it," Bates added.

This version of Joe Biden is certainly more likeable than the nasty old man who Biden was for most of his presidency.