Good question! The speaker has probably used ever twice in one sentence to add extra emphasis. Ever means at any time, so you can understand you ever notice that men only ever do stupid things for one reason to emphasize that men do stupid things for one reason only. The second ever in the sentence is being used to emphasize only.
Ex: You only ever help me with chores when I ask you.
Ex: I only ever drive my car when it's snowing or raining.