I almost always wear cargo pants, a button up shirt and at times a sport coat.

Once on the plane I have my sport coat and dress shirt hung up and put on a somewhat well worn out Sorel hooded sweat shirt. I go from business casual to looking somewhat homeless in a matter of moments.

On one flight , JFK to FRA, I walked the plane to stretch and the FA stopped me from going back to my seat in business class because of how I looked! She walked me to my seat , I produced my boarding stub. When we landed and I put my dress shirt and sport coat back on she came up and said "you look like a whole new person!"