What you're experiencing right now is called cognitive dissonance or cognitive disequilibrium. You've found that the argument you've been making is at odds with the facts. Claiming that you see no difference between a multiply-linked list and a doubly-linked list is an attempt to shrug off a legitimate point with a nonsensical argument. (Or alternatively you are not skilled enough at programming to understand the topic at hand).
What you're experiencing right now is called cognitive dissonance or cognitive disequilibrium. You've found that the argument you've been making is at odds with the facts. Claiming that you see no difference between a multiply-linked list and a doubly-linked list is an attempt to shrug off a legitimate point with a nonsensical argument. (Or alternatively you are not skilled enough at programming to understand the topic at hand).