Mother's Day has arrived, and once again Young Bennett has forgotten to do something for her because he doesn't remember everything she has done for him. To remedy the situation, Old Man Bennett creates an entry to the brain's inner sanctum where they can see everything she has done for them, but when Carla accidentally awakes Young Bennett, Old Man Bennett gets trapped inside his younger self's brain, meaning that if Young Bennett can't find a way back, his older self could be destroyed. To make matters worse, he still needs to figure out what he's going to do for his mom for Mother's Day.