That is a bit different take on. When you are working in a company - if you don't want to have new responsibilities you don't touch it. You touch WiFi router

That is a bit different take on. When you are working in a company - if you don't want to have new responsibilities you don't touch it. You touch WiFi router - well now it is your responsibility if WiFi stops working. You touched sendmail - well as you wrote quotes "expert". But to be specialist on something it still requires quite in depth knowledge than "you were last one to touch it".