Scientists who subscribe to the Big Bang Theory tell us that the Universe is about 14 billion years old and that Planet Earth is about 5 billion years old. Humans, as we know them, have walked upright on the Earth for about 100,000 years and the North American continent has been inhabited for about 15,000 years.
That means that the average life expectancy of about 77 years for Americans is just a blink of the eye when compared in the context of the great scope of all existence. We are only given a finite amount of time in the course of a lifetime; when our term is over we are gone for a very long time. The way we spend our time as conscious beings is very important; it seems a shame to waste even a single moment.
The philosophy of time use is important to both the professional mechanic and the At Home Mechanic. For the professional mechanic, and the repair shops that employ them, time use is a component of what they charge the customer. Every repair facility charges the customer on the basis of the parts required for the job, plus the amount of time it will take to complete the job as broken down in 15-minute increments. A job as simple as replacing a burned out tail light will take less than 5 minutes, but the shop will charge the minimum labor charge of 15 minutes plus the cost of the part being replaced. If the shop is charging you $75 per hour for labor, that fifty-cent bulb cost you $18.75 in labor to replace at a professional service facility. If there is a Great Karmic Ledger of Time Use, the time a professional mechanic trades for a paycheck goes down under the general heading of Business.
But for the At Home Mechanic time spent in the garage working on a car goes down on the Great Karmic Ledger of Time Use under the general heading of Pleasure. I say "general heading of Pleasure" because there are subsets of time spent in the garage that also can be classified as Frustration, Confusion, Pain, and ultimately, Education. Yet the time spent in the garage that may not seem like Pleasure at first still falls under that general heading because the ultimate conclusion of time spent with your car usually ends with a pleasurable conclusion.
Pros work much faster than amateurs; they have the advantage of the just the right tools, the right parts and the right training to get any job done in time efficient manner. The At Home Mechanic may not have the right tools, he may have forgotten to get that tiny but essential part that is required to complete the job, and he is learning as he goes. If a job like changing a timing belt takes a pro two hours you can figure that it will take the At Home Mechanic at least twice that time... the first time he does that job. Even with the best set of instructions from a Factory Service Manual, the rookie mechanic will have a learning curve to overcome.
My feeling is that rushing through a repair job needlessly is wasting an opportunity to spend quality time with my car. Time spent working out the cause and the repair of an automotive problem is an intellectual challenge that must be savored. If you are making good progress on your project there is no reason to hurry. If you finish quickly, it only means that you will have to move on to a job on the never-ending Honey Do list.