Okay, but even that article says, "That means that for some people, changes in the prefrontal cortex really might plateau around 25—but not for everyone." This author's point is that "the age that corresponds with brain plateaus can differ greatly from person to person." For instance, one study found that “Some 8-year-old brains exhibited a greater ‘maturation index’ than some 25 year old brains."

But obviously, most human brains mature closer to 25 than 8. So this is a quibble since my basic point is that, whatever the exact ages, most human brains surely mature after puberty and thus after nature's preparations for human sexual activity. The details are interesting but not crucial to my argument. I'm also not a scientist, so I just deferred to a consensus I found.