Strange …

… Aphantasia: Ex-Pixar chief Ed Catmull says 'my mind's eye is blind' - BBC News. (Hat tip, Dave Lull.)

Most people can close their eyes and conjure up images inside their head such as counting sheep or imagining the face of a loved one.
But Ed Catmull, 74, has the condition aphantasia, in which people cannot visualise mental images at all.