I remember watching my Dad, who was not exactly a mechanical genius, work as an aprtment complex maintenace man servicing 200 units...he was buried in work all the time and had a few doozies...
One time I was watching him work, and I saw him close his eyes and his lips moving for a minute...I wondered what he was trying to remember...
Then he got back to work on the condenser unit, and it fired up and he came over. I said, "Dad, how did you know how to fix that so fast?" He chuckled, "Sometimes, I just say a little prayer, and every now and then it works..."