Her fingers were lifting the elastic in my son's underwear, and as she performed a quick, professional peer at his boyparts, she kept up a running commentary: "This is okay because your mom's here, only your parents and a doctor can look at your body, if anyone ever touches you or makes you uncomfortable, you should tell your mom or dad, okay?"

My son, who was 100 percent focused on the surprise round of pre-kindergarten vaccinations that were next on the agenda, nodded blankly. You could practically see the giant cartoon syringe reflected in his pupils.

The pediatrician patted my child comfortingly and allowed him to sit up and start pulling on his clothes. "Have you guys talked about stranger danger?" she asked.

"Um ..." I said. "We, uh. Not in a matter of ... well, no."

No, I haven't talked to my almost-6-year old about stranger danger. In fact, we were heading into a store the other day—myself, Riley, and my 3-year-old—and an elderly man who was coming in the automatic doors at the same time pointed a finger in their direction and said, "Want to come with me, boys? I've got some candy!" and cackled into my face, tickled pink at his little joke. Instead of reeling away in fear, which was clearly his hope (okay, maybe I'm selling him down a river, but SERIOUSLY, who DOES that?), both kids just stared in confusion, like what the hell, you're not my grandpa.

I guess it's time, right? It hasn't seemed critical before now, since I'm basically with them every second of the day, but Riley will be starting school in a few weeks. I suppose that's about the time you start worrying about twisted freaks who lure children into windowless vans. I suppose we need to talk about Inappropriate Touching, and Not Talking to Strange Adults, and basically starting the process of removing, layer by layer, that innocent belief that nothing can hurt them.

Riley has always been a bit of a hesitant kid, and he's only recently started talking to random people when we're out and about. Just yesterday he asked if he could talk to our neighbor, and came running back with the breathless announcement that the guy had given him permission to look in his yard whenever Riley lost a ball over there. And my brain went: hurrrrrrrrnk. Because I don't want him to live in a world where I'm not entirely sure if I should allow that or not.

(Maybe he can just be better about not throwing shit over the fence, right?)

He loves to call out "Hi!" to passing strangers, he loves to ask the guy at Home Depot what he's using that tape measure for. I hate the idea of squashing this new outgoing side of him. Of peeling back the world he knows, where everyone is perfectly happy to interact with him and would never in a million years do him harm, and give him a glimpse of what's underneath: a murky swirl of what-ifs. How can I give him confidence and caution at the same time? How can I tell my child that there are people who might try and touch him, or worse? How can this even be a thing that is true, because my god, my god.

There's so much I'm not ready for. Lately I suddenly feel this very real sense of this age, and everything that is sweet and innocent about it, running through my fingers like water.