Why can one-question bites beat a packed lesson when the idea is new?

Answer: Working memory stays unjammed

Less boredom during lesson — Boredom matters for attention, so this is a believable guess. But the cognitive-load point is sharper than entertainment: even a fascinating lesson can overload a beginner if it introduces too many relations at once. Attention is only the doorway. Working memory still has to hold and manipulate the pieces.

Working memory stays unjammed ✓ — Right. Working memory holds only a small amount of readily accessible information, while long-term memory can store richer schemas. Cognitive-load theory says instruction can fail when working memory is overloaded by unnecessary or too many elements. A single question can isolate one mechanism so the reader can actually operate on it.

More key-term repetition — Repeating a key term can help recognition, but repetition alone can create familiarity without usable understanding. The hard part is connecting the term to a mechanism without juggling too many new pieces. A one-question bite can repeat less while structuring more. It makes the relation operable, not merely familiar.