I've heard this urban legend from the platform, but a quick search of few year's worth of Watchtowers did not come up with a quote. This is the closest I found.
Is Everlasting Life Really Possible?
13 Does this mean that there is no way to gain everlasting life? Not at all! There is a way! The structure of our marvelous brain, with its virtually unlimited capacity for learning, should convince us of this. Molecular biologist James Watson called our brain “the most complex thing we have yet discovered in our universe.” And neurologist Richard Restak said: “Nowhere in the known universe is there anything even remotely resembling it.” Why would we have a brain with the capacity for storing and assimilating virtually unlimited information and a body that is designed to function forever if we were not intended to enjoy everlasting life - Watchtower April 15, 1999 P. 6