When someone has done the same task for years they can tend to fall into a rut.
This is just the normal progression of things and can happen to the best of us.
This was absolutely the case when it came to our Heating and A/C contractor. He was a good guy, always showed up promptly for appointments, and never gave us any cause for doubt in his abilities; When he told us that he was retiring the two of us upset that the two of us would have a new 1 that was not as know-howable. On his last visit he brought along his replacement and I was shocked to see that it was a kid just out of trade college, and my first thought was to call the Heating and A/C supplier and tell them that the two of us wanted a more experienced person laboring on our plan however our partner insisted that I provide him the benefit of the doubt. That appointment went about fairly normal however on the next service called the two of us got some information that the two of us were shocked about. The new contractor said that he had tested the ductwork and found that there were several areas where there leaks. This meant that the two of us were losing overheated and cool air each time the two of us ran the system. I question him to see how something appreciate that could have happened so suddenly but he indicated that the leaks had been there for several years at best. This had myself and others questioning the abilities of our former contractor and wondering why he would not have done the same test. This new person is going to end up saving us a significant amount of currency on our fuel bills and I am genuinely grateful that he has a your way of thinking when it comes to repairing and maintaining our heat and air conditioner.