Are you being sarcastic?
No. My point was that older people generally already know how to start a car. They will automatically fill in missing steps. For example. if you tell an adult to insert the key, rotate to the ignition position, then rotate a bit farther to the start position, wait 5 seconds, then rotate back, the adult will know that you mean wait no more than 5 seconds to rotate back. They will rotate back as soon as the engine starts.
They will know what it takes to set the choke, if the vehicle has an automatic choke.
The 10 year old will know none of these things, so you will need to provide very clear directions - the kind that can be implemented in code.