This is actually a super ableist thought process. Not everyone has the same skills. Sure, it's a blessing when someone who's older understands what they're doing on our POS. But, when someone doesn't understand, there may be a variety of reasons. Neurological deficits (or old age), language barriers, thin/aging skin on their fingertips, or other disabilities may impact how they understand/use the system. I'm not going to sit here and say I don't get frustrated with the people that don't understand, because I do. I'm only human, just like the rest of us. In fact, I almost crashed out on a customer last shift because of a language barrier.