As a person who lives with someone who does this all the time, I can assure you, they didn’t understand. People who do this aren’t paying attention to detail, so while they may have a general idea of what’s being said, any specific points in the conversation that don’t fit the general script, get unheard because they’ve either already cut you off or are too busy thinking about what they’re going to say next. Then when it comes to doing said task, behold, they make careless mistakes