Front of the queue effect
You are standing in a queue waiting to buy food, order drinks, or buy tickets. The queue is long and is moving slowly. You are grumbling about the people standing in the front, why are they asking so many questions, why can’t they make choices beforehand. And then your turn comes. You are prepared. You know what you want. But it took so long to reach here. why not confirm your choices? After all, you stood for so long, at least you can spend a minute or two confirming that you are making the right choice. If you made an incorrect or an incomplete order, who would stand again in this long queue to correct it?
Longer the queue becomes, slower it ends up moving.