On an early-summer day at the grocery store, you might notice a sale on watermelon and think you should buy some. That would be a mistake. A sale on watermelon means the store wants to get rid of surplus garbage fruit.
If you buy some anyway, you might get home and decide to carry a bag of your other groceries in one hand and the melon in the other while attempting to operate the door handle and greet your happy, beautiful dog jumping up at you. That would be a mistake. Your watermelon will roll out of your hand and split in half on the floor.
You might think the logical response to the splattering of your melon should be to exclaim as loud as possible the most vile words you can imagine. That would be a mistake. Although it is indeed the logical response in that moment, you should realize your spouse is one door away on an important work-related phone call.