What is the meaning of the idiom "Que cosas!"
I don't know whether it is used differently in other countries, but in Spain it does not mean "What the..." or anything similar. It has different translations depending on the context and the tone, but it expresses strangeness, surprise, amazement. It is often a short for "¡Qué cosas pasan!". I'd say is more like "That's curious!", "That's quite something!"...
I was going to say that´s weird or that´s strange.
I have just looked at our dictionary and it says, qué cosa! -> how strange!