What are people like who are in comas and do they often remember their coma state?

My dad went into an induced coma after getting a traumatic brain injury, and he doesn't remember anything from the comatose stage itself or even much of anything that happened during the weeks after he woke up from it. Once people wake up from a coma, it's very common that they face a rehabilitation stage where they need to learn basic skills such as movement and speech all over again. It's kind of like having the brain of an infant; people don't really remember things from the very early stages of life because they didn't have the brain capacity or memory to store that information; it's the same for coma sufferers.