What do you think he means by "20 years of keystroke data"?
From the 12 December 2009 issue of New Scientist:
"I'm an information pack rat," he [Stephen Wolfram] confesses. Recording our interview is just the tip of his peculiar obsession with documenting every moment of his life. "I have a keystroke logger that has collected my every keystroke for the last 22 years," he says. "Every day I get an email that tells me how many keystrokes I typed the previous day into each application. I find it slightly interesting." He shrugs off my suggestion that it's a way of securing his immortality; he believes that soon everyone will be doing it.
Which, if any historians become fascinated with Wolfram, would be an amazing boon.