Wedged into the copy of Forever… that I downloaded as research for this review, just after the dedication and just before chapter one, is a note from author Judy Blume. Though the book was first published in 1975, this particular section was only added in 2014, to offer more up-to-date information about Sti prevention.

It’s a tiny addendum, really — one single page — and everything that follows otherwise reads exactly as it has for the past half-century. Yet it speaks volumes to both the novel’s enduring popularity and to Blume’s willingness to reconsider her own classic in a more current context.

The changes to Netflix’s new take on Forever are far more sweeping, and altogether impossible to ignore. But seen in that light, the updates look less like a refutation of the original than an embrace of its spirit, executed with enough freshness to stand on its own and...