Some books have great hooks and ideas that drive curiosity.

But a simple dead body and a whodunit? isn't enough on its own. All the normal writing rules apply. We need to care about the characters, to sense the conflict, to appreciate the descriptions, dialogue and prose.

As well as the momentum and pace of the plot, I think our mood as readers has a role to play.

If you've picked up the book 5 times during a stinkingly bad week or failed to get past 2 pages due to exhaustion, it can reduce motivation. Everyone is dofferent of course.