A woman I know gets great recipes from her mother. The mother sometimes will give the recipes to people outside the family, but will change an ingredient or two or change the amount of an ingredient. Then she'll turn to her daughter and whisper, "Don't you use that recipe. I'll give you the right one when we get home."
My own recipe-sharing story is this. Many, many years ago, when I was in college, someone made these really fantastic cookies. Really, really good cookies with a chocolate kiss inside. She would not share the recipe. So, because these cookies were so good and I'm a pretty good baker, I started out to duplicate the recipe. Finally, after a few trials, some errors and at least two cookie batches that went straight to the trashcan, I had at least a reasonable facsimile of the original cookie. I liked them, my friends liked them, my family liked them.
For a Christmas party at my dad's house, I made a batch. Someone asked me for the recipe. I'm always incredibly flattered that someone would want one of my recipes that I am more than willing to share. I started to give it to him and my brother interrupted. "You can't give him that! It's a secret family recipe!" No, it was MY recipe. But the family decided that I couldn't give it out to anyone outside the family.
That lasted at least 15 years, until I found out that the same brother who wouldn't let me give anyone the recipe had given it to his girlfriend. But that was different, you see.