You can read a hundred explanations of a linked list and still freeze when someone asks you to reverse one in an interview. You know the definition. You've seen the diagram. You've even solved the problem once, last Tuesday, with the tab still open.
The problem isn't knowledge. It's that you've never watched one work.
The gap between diagrams and intuition
Every data structures resource falls into one of two buckets:
Textbook mode: prose plus a static diagram. Here is a linked list. Each node points to the next node. Great. Now solve "reverse a linked list in O(n) time" and good luck.
