We normally have all the necessary tools to get the repairs done right there in your driveway! If we have all the information about the problem and what brand, model, type of machine we're dealing with, we can usually get most parts before we come out!
First, meeting new people and making them happy. Second, simply the challenge of the repair itself. Like an artist who admires their work once completed, I enjoy the same. Taking something that does not function right and making it right is a great feeling! That and the smile from the customer make it all worth the time and effort....