The more examples you read the easier you can recall this stuff. I find the single to two teller examples very compelling myself. How quickly a line can build up and how long it lasts when people/tasks are arriving at 90% of capacity and you get one burst of extra traffic is quite shocking the first time you understand the math.
for context: 10 yrs experience as a software engineer and only a couple on high traffic products. Some things (like this) continue to surprise me.