When making long noodles. Make a circle with your thumb and index. Bring your index all the way to the base of your thumb. Somewhere in there is the amount you will eat (of dry noodles that fit). Find it, and never make the wrong amount again.
Yeah I always learned the same: one serving is approximately a circle from index to base of thumb, two people you move your finger up the next crease in your thumb, 3 you just make a circle of tip of finger to tip of thumb. It isn't always perfect but it has served me.
I can relate! I've learned to measure my pasta by weight. I know how much my household cares to eat, and I cook that amount or a bit more for leftovers.
I do the same. To add, 1 portion is about 120-150g depending how much you like to eat. And for those who asks how to weight spaghettis, put 1 glass on balance, do the tare and put your pasta.
A bit out of left field but wanted to share one of the best standup comedy premises with a pasta joke at the end. Mekki Leeper talking about how he stalks his ex on her food blog because it's the only social media platform she forgot to block him from