Most days I look and walk like any other middle-aged person, most days. Other days, well, not so much.
Because of my age and appearance as fairly fit adult male I get a lot of grief when I do use a handicap spot, and that's isn't very often.
In one particular instance a guy who looked to be some 10 or 15 years older than me vocally objected to me parking in a handicap spot (that he wanted to park in). Long story short the exchange drew the attention of both mall security and local police. It turns out the other didn't have a permit, it was for his wife, who was at home, and he was stopping to pick up some stuff after a round of golf. He had just walked 18 holes!
The police politely informed him the permit could only be used for the person named on it, and that my permit had MY name on it.
Unfortunately it's nearly impossible to enforce that requirement.