I have to confess that the reason the heating element in my oven burned up yesterday is because something had boiled over on it and it needed to be cleaned. I debated about whether I should clean the oven before doing cookies and decided against it. There is a superstition in my family about that, and we never clean the oven shortly before having to cook for a holiday when the oven will get a work-out.
The superstition is borne from an experience when I was a child and we were hosting Thanksgiving dinner at our house. The house was full of aunts, uncles and cousins all looking forward to the 24 pound turkey my mom had in the oven. About noon, Mom noticed that she couldn't smell the turkey yet, so she went and checked on it and discovered the oven was stone cold -- and so was the turkey!!
My handyman dad tried to fix it, and after examining it, declared that a wire had broken leading to the heating element and that it would have to be replaced. Since there was no way to get parts on Thanksgiving Day, there would be no turkey cooking in that oven. My mom had cleaned the oven the day before, and apparently when she lifted the heating element to clean underneath it, the wire broke.
My parents checked with the neighbors for an available oven, but, of course, theirs were all in use.
We had Kentucky Fried Chicken for Thanksgiving Dinner that year ... buckets of it.
The next day, my dad fixed the oven, my mom cooked the turkey, and everybody came back for a turkey dinner with all the trimmings.
To this day, we still talk about the Thanksgiving we had KFC.
And nobody in my family ever cleans their oven just before a holiday.