Remembering numbers is a form of mental exercise that we used to engage in regularly, and as exercise it was good for the brain, just like stretching. You seem

Remembering numbers is a form of mental exercise that we used to engage in regularly, and as exercise it was good for the brain, just like stretching. You seem to have the implicit model where the less we burden the brain with mundane tasks, the better, as if we had a fixed daily capacity for thought, or that mundane tasks are somehow wasteful. I'm not sure this is the case--neither that mundane applications of brainpower is burdensome, nor that capacity is fixed. I suspect that someday, after more and more mundane mental tasks are replaced by more automation and better design, a market will emerge for mental fitness clubs to help thin the "fog" that will come to characterize our mental lives..