Past: Grandma's Interesting Gesture

The time? Let me think. I had to be about nine years old at the time, so we are looking at roughly 1996ish, give or take. My grandma and I were heading into the village district of the town I grew up in. I don't remember the case, we were probably going for groceries or something like that, but I remember we were turning left on to another street, when somebody did some traffic maneuver not to my grandma's liking, and then she stuck her arm out the window and made a gesture that I had never seen before.

 
After we came back to my house, Gram (which is what we called her) and I dropped off our recently purchased goods and settled in. If I am not mistaken, I don't think the mysterious hand gesture ever came up in discussion at all that day. However, a few days later, it came up in conversation. I believe that my grandma was baby sitting me and my siblings, and she overheard me make a reference to it. Oh, wait, was it my older brother who happened to bring up the gesture and I said something to the effect of, "Gram did that the other day when we were going to the store!" I know that I'm a little hazy on the details so far, but after I said that, I remember the next part really well.

   "WHAT?!," exclaimed my shocked grandmother. I was confused. In my mind, I simply relayed facts of what happened. It wasn't anything more scandalous than talking about cartoons, or making fart jokes. From there, my grandma went into hysterics. She was literally crying and telling me that she would never speak to me again. I'm telling you, I was confused, if not completely blindsided by the way she acted.

Eventually, my older brother, who was petting my defeated, weeping grandmother, convinced me to apologize to her. She scolded me and told me that she wouldn't speak to me if I was going to say such horrible things about her. I made a promise that I would never say anything like that about her again, and then her attitude subsided. I don't believe that I ever spoke a word of this to anyone ever since. This does not mean in any sense that I didn't think about it ever again. No. If some experience sticks its big traumatizing foot into my bear trap of a memory, I will never let it go. This was a bear of an experience, let me tell you what.
    What made this memory so hard to forget? In a word: overreaction. I stupefied by how badly my grandma freaked out. I wasn't the kind of kid to disrespect adults, and I was a very truthful tyke to boot. So here is the big question: did I make up what I saw, or was grandma's act a big, fat cover up? Was she such a lady of character that a minor tarnish threw her into a rage, or did she not want my little lips repeating what I said earlier? Either way, she got what she wanted. You decide, I'm done.