I used to think this quote is annoying and stupid - when you have a single clock, you always trick yourself into thinking that the time is """correct""", but wh

I used to think this quote is annoying and stupid - when you have a single clock, you always trick yourself into thinking that the time is """correct""", but when you have two you'll usually be confident within a margin of error. This is why the International Atomic Time is derived by averaging many atomic clocks, or how NTP gets time from multiple servers. But on second thought, it can also interpreted as such: in a large synchronous system, it's often important to have a standard reference clock and to lock all the other clocks onto main clock, otherwise the system can be inconsistent due to timing problems, e.g. distributing a frequency reference in a lab, distributing the clock signal on a circuit board, or distributing standard wall clock time via NTP (the Stadium 1/2/3 hierarchy). So the quote makes perfect sense again.