From LATimes.com:

“I don’t feel lonely,” Clinton claimed. “But I do feel sometimes isolated. Because when you are in these positions that I have been in, it can be very isolating. It is one of the reasons I put on the dark glasses and the baseball cap and go out of the White House. President Harry Truman once said that the White House was like the crown jewel of the American penal system because you can feel confined.”
“And kind of jails,” Banks added.
“Yeah,” Clinton replied. “Because you feel so set off and really isolated.”