One of Iain M. Banks’ Culture novels has an exceptionally old character who is so exceptionally old that he’s had to turn most of his body into memory storage (sounds weird if you think in terms of computers) to keep remembering things. He stores his sexy memories in his balls.
He’s in Hydrogen Sonata. The mcguffin guy who everyone is trying to find and talk to because he’s the only person who’s old enough to remember some very important thing about the early days of the Culture.