Biden took some personal notes home. These were used to write a memoir. Biden fully cooperated, and returned all documents when asked. Similar to Mike Pence and many others.

The special counsel seems inept. How many criminals has he let go because he thought they had a memory excuse? Mixing names up and getting dates wrong is common, its just the way the human brain works. Shouldn't a special counsel know this?

Mixing up names like Biden and Trump have done is pretty common, February 10, 2024
"Some studies have suggested that everyday “misnaming” may occur when the brain has names stored by category — like your family members or perhaps in Biden’s case, world leaders he’s long known — and grabs the wrong one. Or the miss may be phonetic, as the names of France’s current president, Emmanuel Macron, and former President Francois Mitterrand both begin with “M.” Mitterrand died in 1996. As for dates, emotion may tag certain memories but not run-of-the-mill ones, such as the special counsel’s questions about when Biden handled a box of documents. “Attaching a calendar date to an event is not really something that the human brain does at any age,” Lenze said. It’s “not like a spreadsheet.”"
apnews.com - Biden trump age concerns analysis verbal gaffes