This is pretty awesome.

Among pallets of paper towels and bottled water, Hillary Clinton spent more than three hours Saturday morning autographing copies of her new memoir, “Hard Choices,” at a Costco in Northern Virginia.

And, as it turns out, you really never know who will show up.

“I don’t believe this,” Clinton said as she embraced Supreme Court Justice Sonia Sotomayor across the table.

Justice Sotomayor said she happened to be “just shopping” at the bulk discount depot when she spied the former secretary of state sitting down. She told Clinton she plans to read her book.

“You better, I love yours,” Clinton responded.