Why can one leading question rewrite what you remember seeing?
Ask a witness how fast the cars smashed, and they will remember a worse crash than there was.
After you witness something, any information that arrives later can quietly fold itself into the memory. Your brain does not replay an event like a recording; it rebuilds it each time, and post-event wording, leading questions, or someone else's version can swap details in without you noticing. The new memory feels exactly as real as the original.
Two friends argue about a dinner from last month. One keeps saying "the waiter was so rude," and after a few retellings the other genuinely remembers a rude waiter who was actually perfectly polite.
How an event is described to you afterward can edit your memory of it, and the edited version feels just as true.
Be careful how you ask people to recall things, and be skeptical of your own vivid memories after you have heard other people's version of the same event.
Memory is wet cement: whatever you press into it afterward leaves a mark.
Learn the idea and practice English at the same time.