person A: I was trying to explain to a friend why something is happening and they just couldn't get it. I don't get why they couldn't understand me. 
person B: ohh_comma_ what did you try to explain them?
person A: I was trying to explain to them why the Great Recession was caused by the recycling of petrodollars and an unrestrained financial market. 
person B: Ohh_comma_ sometimes people don't understand simple things. I think the words like 'petrodollars' might have confused them.