Do those who have schizophrenia remember everything that happened after they've had a psychotic episode?

Sometimes: It can depend sometimes on the type of schizophrenia one has. It also varies from person to person. Some may remember every detail while others remember nothing.

Most of the times: Schizophrenia is not a memory disorder. So there's no reason for sufferers to have memory loss except for things experienced at the worst stages if a psychotic episode associated with confusion (not all are). Sufferers of this illness may appear to have memory problems partly coz they may not like to talk about symptoms experienced in past, or about their behaviors under influence of those symptom.

It depends: Every person is different. While many people tend to forget some parts of their thinking and behavior during a psychotic episode while remembering others, there are also some individuals experiencing dissociation that may not remember anything. Memory can also be negatively affected by medications used to control the episode.