no joke, but how about a story?
about 10 years ago, my grandmother had every thing done for thanksgiving except the gravy. after simmering the gravy for for several mins, she relized it was to thin, so she reached for some cornstrach. She added some, it would not thicken, so she added some more, and then some more... it still would not thicken, she finally said screw it and put it on the table...
that when we found out, it was not corn starch, it was powdered suger she was adding

yes, every year no matter who makes what, in my family we always ask if there is powdered suger in the gravy.