If there's a Doubt, there's No Doubt
Now I only wish I were as good at this as I am about "Don't drink your calories, unless drinking alcohol," although it really didn't help me when I tried to classify ice-cream as a liquid (ice-cream is oddly tied to geography for me).
I suppose we could classify this in the "we're too poor to buy cheap" category as well. You should check out my son's blog; he has a field day skewering ridiculous sayings. Compound interest maybe. (A non-sentence works sometimes too). I'm reminded of The Tale of a Nail, which I read for my college freshman writing seminar (the odd things we remember). This was it's refrain:
Save a nail, bad or worse. One may it may fill your purse.
It was about a peasant who saw a nail come lose from a squire's horse's shoe. He told the squire, who couldn't be bothered, and rode on. The peasant pocketed the nail. As you can imagine the squire's horse became lame and the squire was caught out to his misfortune.
The peasant on the other hand, came upon a lord and his carriage in a bit of a conundrum. The nail is useful in reattaching the carriage wheel (I picture this as the ancient equivalent of the cotter pin that holds the nut that holds the hub on the axle of your car if you have one, or maybe it replaces the nut as well). The lord can move on in his manner to great benefit, and as a consequence, benefit is likewise showered upon the peasant.
Stupid f-ing story, or maybe it's a matter of proportion. Perhaps it should be "Waste not, want not, but don't bury your own ass under things because they might one day be useful."
So I wake up this morning to the fluttering noise of the vent in my bathroom, but not because of it thankfully. And annoying as it is, I'm more annoyed by the fact that I didn't put them in the other bathrooms. They have nice big windows, but that doesn't help in winter, and one is in a corner where my architect should have been able to predict (I suppose I could have too) that there would be little flow of air.