Explain This To Me

So, I've owned a poofy vest for about 5 or 6 years now, and only worn it a few times. That is because I feel, deep down, that it should be a useful garment, and I am unable to get rid of it, but really, I just don't see the point. Extremities, like arms for example, are the part of the body that get cold fastest, so if it's cold enough for me to pull out my poofy wardrobe, would I choose something that ensures I will freeze my arms off? Sure, you can layer the sweater or sweatshirt underneath it, but in my last foray into poofy vest wearing, I wore a hooded sweatshirt and a hat and gloves to ensure adequate warmth and then walked all over DC, and I'm pretty sure at least 3 people thought I was homeless. Do you wear a poofy vest? And can you explain the logic/situation in which it's applicable?