Sorry I have to disagree here as well. I do not think the time or number of commands or typos should be measured. I do not think you can do any quantification here. I believe a lot of sysadmins (talking about unix) do w;uptime;inspect syslog as soon as they connect to the system. Most of the time it's just not necessary to do this but for a lot of sysadmins it's a habit that actually saved their asses several times.

Does it make sense for a sysadmin to know a numeric notation for chmod ? Probably. Would I ask that on an interview ? Nope If you need to ask why then you have probably never worked in a heterogeneous environment.