A GREAT TRICK TO PLAY ON YOUR KIDS

Tell them that elevators arrive based on how rapidly you tap the Call Button. Same thing with crosswalk signals - the faster you tap, the sooner the signal changes.
While they'll be silently mocked for decades to come by people-already-annoyed-because-they're-being-forced-to-wait, think of the sense of self-worth and accomplishment they'll feel when the elevator doors open or that orange hand turns into a white robot in mid-stride.