Things I've learned:
1/4 cup dried minced Onion is not equivalent to 1/4 cup chopped fresh Onion. Not at all.
This was the first thing I learned. It was a very onion-y meatloaf. I was in about the 7th grade.
Hot tap water is not the same as boiling water. Nope. Huh-uh. It's not. The Jello won't dissolve in tap water. And no, it won't set up if it doesn't dissolve.
Found this out the hard way. But our Sunday dinner company was gracious and ate the Lime Pear Pudding Sauce without complaining.
It is possible to flop a cake mix. Twice. In one day.
Don't grease your pie plates when you are baking pie shells. You'll end up with 5-inch cookies that taste like pie dough. And you'll have to re-make the pie dough.
Make certain that your Crock-Pot works. Before you invite company home from church.
Check to see if your honey even likes Artichokes before serving them as the main dish.
It is possible to burn the bottom out of a brand-new pressure canner on the first use.
It's a long story.
Always seed the Jalapenos before canning them.
What have you learned?