Only a dare­dev­il makes metaphors. To make a metaphor is to walk a tightrope, to be shot out of a can­non, to do aer­i­al som­er­saults with­out a net. The trou­ble with metaphors is you nev­er know when they’ll let you down. You turn a som­er­sault in midair, you reach for the trapeze, and sud­den­ly it’s not there.