Hi Lisa,
Yes there was "instant pudding" by Jello that was available in the 70's that did not require cooking. That was the kind that clearly said Instant on the box. The regular Jello Pudding that needed to be cooked did not say instant on the box, even though it was a mix.
The instant needed to be mixed at high speed, with a mixer, to make it thicken. And you're right, it is very gritty when done.
I have tried the Instant Jello Dark Chocolate Fudge pudding and it's pretty good, low in carbs and a quick chocolate fix when you just have to have something sweet.
But, of course, my favorite pudding is homemade, no mixes, and made with heavy cream instead of milk! Now that is decadent.

OK maybe my boyfriend isn't insane then, he swore he had a no-cook pudding growing up. We *always* had the cook pudding and it never occurred to me that there were other kinds. I'm definitely not a fan of the grittiness but I imagine it's all what you are used to

I like the no cook kind as I hate cooking anything. No cook, no sugar! Then a dollop of cool whip and you have a decadent dessert that's low carb!