Like the rest of us, President Obama apparently looks back on the height of birtherism with amused bewilderment.

Addressing the 2014 national conference of Rev. Al Sharpton's National Action Network in New York City this afternoon, Obama delved into the subject of voting rights-a topic that came up at the LBJ Library earlier this week, and at August's March on Washington anniversary, as a major priority for civil-rights groups like Sharpton's.

"Just to be clear, I know where my birth certificate is, but a lot of people don't," Obama joked, making a point about ID requirements at polling places.

Grinning, he continued: "Do you remember that? That was crazy. That was some crazy stuff. I haven't thought about that in a while."

Birtherism-the theory that Obama was not born in Hawaii, but in Kenya (or Indonesia)-reached a crescendo one morning in April 2011, when birther-in-chief Donald Trump landed in New Hampshire and held a press conference at the airport, amid a torrent of rumors about and fascination with his potential interest in running for president.

Obama held a concurrent press conference at the White House, releasing a copy of his birth certificate, mostly (but not entirely) silencing those who claimed he was not eligible to be president.