In days of yore...
I worked for a well known mainframe company, I was a field engineer team leader with responsibility for about 6 customers in central London. When I was appointed to this role I spent about 6 months in constant contact with 'my' customers educating them on how to fix common trivial problems, how to pre-diagnose problems so when they called me I had a better idea what was wrong and could go armed with the necessary resources, parts... After all this my team call rate went from about 5 a day to 5 a week and my customers were as happy as Larry- I was well chuffed.
My manager wasn't happy - because we weren't running running around like blue-arsed flies all the time doing stupid things like cleaning read/write heads on tape drives, removing paper jams from printers, bursters etc.. he called us a load of idle bastards and we all got poor annual reviews!!!
Shortly after I told said manager he could stick his job where the sun doesn't shine and left.
So, don't curse those 'trivial' calls, they may mean job security and good pay rises.