Mrs. Incredible(ly stupid)!

I did something incredibly stupid today and just now, at 8 pm, did I realize it. First, I'll give you a bit of background leading up to my temporary loss of cerebral function.
Piglet is tall for his age. He is no longer able to stretch out in his firetruck toddler bed. So I've been looking for a big boy bed. Piglet's friendfromschool has a loft bed, which is basically a bunk bed without the bottom bunk, and he's asked for one no less than 87,000,000,000,000,000 times. I've been to furniture stores (what is UP with all the furniture posts?) and online and refuse to pay upwards of $700 for a child's bed. So, hellooo, Craigs List. Gotta love Craig. I found the perfect loft bed for sale for $120! Here in my town!! I emailed, he still had it, I called, said can I come look at it, he said sure, gave me the address. So without telling anyone where I'm going (which I never do), I pop Piglet into the truck and we're off.
We show up at the house right on time and ring the bell. A pleasant looking man in his late thirties opens the door and in we go. He says his younger son still has his bed set up, did I want to see it? Of course! So we go upstairs and see the bed. It's fantastic, I must have it right NOW. Sure, perfectly-harmless-in-no-way-threatening man says. The unassembled one is in the basement.
At this point, shouldn't some form of common sense have kicked in? I have my child with me. The one who counts on me to protect him. Did any maternal warning signs activate? Suggest that since it wasn't a good idea to come into the house in the first place, that perhaps it is a worse idea to go into the basement with this man? Why no, not a one. The basement? Sounds fun! Let's go.
Obviously, it all turned out fine, or I wouldn't be posting this. But it very easily could've been different. That man was alone in his house. No one knew where we were. I had no means to defend myself, plus I was in a strange house. Remember Jodie Foster's basement scene in "Silence of the Lambs"? Ok, it's a stretch, but it still could've happened. I had no appointments scheduled, I only answer my phone if I feel like it, and the husband wasn't due home for five more hours. He wouldn't have started worrying until around 8ish. Lots of time for a bad man to hurt a woman who was dumb enough to come to his house alone in the middle of the day. And her little kid.
Sometimes I wonder how I've made it to forty years old. Seriously, there are probably hundreds of situations I've been in that I should have been harmed. I've been lucky, but I must stop relying on luck and be smarter. Piglet doesn't know any better, but I certainly should.