Chocolate shake as a treatment?

Here's something interesting. For 46 years since diagnosed I've stayed away from ice cream and shakes thinking that the cold would aggravate the migraine and make the pain worse. Well today I had an attack, taken Excedrin migraine which only dulled the pain this time. I was with my niece and she wanted to stop at McDonald's for a chocolate shake and asked me if I wanted one. For some unknown reason I said yes and to a large. Drank it down pretty quickly (you can't just sip). Got home and laid down on the couch then I realized the pain was completely gone. Has anyone else have this happen to them? Could this be a coincidence? I don't know but I think I will try it again and see what happens.