I have used the word "overthinking" alot in diagnosing new diver issues, and it does apply to new skills and experiences for certified divers. Overthinking ends when familiarity from repetition replaces it. Experience is the key to these things. Rescue diver stretches divers out of their comfort zones on purpose. Remember in emergencies to stop, think then act. Thinking is only overthinking when it is to the point of unnecessarily delaying action needed to respond to the emergency. Practice responses to the extent you can, talk through scenarios, read about real life situations. Maybe start a " this is what happened and this is what we did" thread here. you'll do fine in the class. Build on it with further practice, repetition, and by being an active diver.
DivemasterDennis
DivemasterDennis