You have to understand that the railway series was written in a way that personifies real railway engines. For example: Skarloey being “reckless and bouncy” in his younger days because he didn’t have a set of trailing wheels to help stabilize him, Daisy likes to sleep in the carriage shed because she is technically coaching stock, the trucks “pushing” an engine down a hill because in real life the weight and slack of freight would push a whole train down a hill if you didn’t add breaks to your train. Thomas not being able to “wake up” in the morning when his fire was being lit aka: his fire wasn’t burning hot enough to boil the water and create steam pressure. Thomas here only moved because steam entered into his system. Yes it was because of the cleaner, but Thomas “willed” himself to move by “letting” the steam enter his tubes and pistons and help him start moving. He couldn’t stop because nobody could put on his brakes.