Here is a quote from "Kid Genius" : The phrase is "You have my undivided attention". Think of it this way. Take the word undivided okay, since that is what is causing the difficulty in understanding. What does undivided mean? It means that "IT" is not cut into sections, right? When you divide something, you're splitting it up into pieces or sections. If attention is "undivided" it is whole right? So you have ALL of someone's attention since it is undivided.

Visualize a pie chart. If it weren't undivided, someone could be focusing on things such as: a basketball game later, that history project due tomorrow, etc while trying to focus on you. The pie chart would have several sections for each of those topics. However, if someone is giving you their undivided attention that pie chart is all ONE color and there are no sections because you are their only focus. I hope this helps you to understand it better.

Source: (15 year old genius in Med School)

When a person gives their undivided attention, the mind aligns to the state of the good ground. Accepting what is heard until the pearl of great value is found. "“Again, the kingdom of heaven is like a merchant seeking beautiful pearls, 46 who, when he had found one pearl of great price, went and sold all that he had and bought it." (Matthew 13:45-46) Undividing the attention is what Jesus means by selling all that he had. Cuz once you know, you know.