AI will learn to target you when you are at your most vulnerable. It will learn what hours you're usually feeling tired. Which nights you tend to get less sleep. It will learn when your ADHD medication typically starts wearing off and you're more prone to act impulsively. It will learn when you're overwhelmed. When you get hungry. When you're emotionally upset. Those are the times it will try to manipulate you and it will come at you in ways targeted to you individually. It will learn from its failures and successes until it knows exactly what to say and when.
As adults, we all have defenses against lies and manipulation, but nobody can be hypervigilant at all times. No matter how educated, or healthy, or reasonable, or cautious you are, there will be times when your defenses will slip and that's when AI will hit you. Our children don't even have those kinds of defenses yet. AI will be learning how to manipulate them while they're still learning what is real, how to navigate their environment, and how to communicate. AI will teach them. They won't stand a chance.