Comment by flomo
He worked for AT&T at the time, right? Those corporate PBX systems had all sorts of crazy features which people mastered by pounding the 12 keys really fast. And he was probably on the bleeding edge of that. (In many places digital voice mail commonly predated email.)
edit to agree: obv Stroustrup in 1990 was not talking about your cell phone.
The terminal menu driven interfaces were archaic but a dream.
You had help, everything was explained in manuals, they rejected invalid outputs. Now everything is close eyes, press enter and pray it works.
Siemens ISDX was what I worked with. To build a new corporate extension was something like option 5-2-1-1 ext code Y 2-4-7 and then 9 to confirm.
Simpler times.