First time I took my truck to the local oil change place, they had no idea how to start it. They had to come and get me. They were all amazed when I turned the key, stepped on the starter and the truck fired right up.
In cases like that, it's even more fun to get in the truck, turn the key to on, hold both of your hands over the dashboard, and say "Start, truck" while hitting the starter with your foot. Some of the expressions you will see are priceless.
A downside of not telling a shop how to start the truck is that they can twist the ignition key until the ignition switch or key breaks.
