The phrase 'let the reader understand' has this old-school charm that feels like it belongs more in religious texts or classic literature than in modern writing. I stumbled upon it while reading some older novels, and it struck me as a bit of a relic—like something you'd find in the margins of a medieval manuscript. These days, writers tend to favor more direct engagement, breaking the fourth wall in subtler ways or just trusting the reader to pick up on clues without being explicitly told. That said, I do see it occasionally in meta-fiction or postmodern works where the author plays with narrative conventions, but even then, it's rare.
What’s interesting is how modern storytelling has evolved to rely on 'showing, not telling.' Instead of instructing the reader, contemporary authors often weave understanding through dialogue, imagery, or pacing. Take something like 'House of Leaves'—it messes with your perception without ever saying 'let the reader understand.' The phrase feels almost quaint now, like an artifact from a time when writers assumed readers needed hand-holding. Still, there’s something poetic about it—like a little wink from the past.