When we are asked to focus on something, we usually tend to just think, look and understand about that particular topic. Nothing else. By doing so, we have the tendency to overlook some important things. We miss what is already right under our noses.
Here is a video that can demonstrate what I'm trying to say. Listen to the instructions; make sure you follow what the guy tells you to do. Ready?
under someone's (very) nose - right in front of someone or in someone's presence
Thanks for clicking.