Lazy and ignorant

What a combination. First, the lazy: My wife picked up a couple new shirts for me about 3 weeks ago. I still haven't tried them on. I also picked up some extra smoke detectors several weeks ago, before the clocks changed, as well as some extra 9V batteries, as I wanted to have more detectors in the house, and we were overdue for changing the batteries in the ones we had.

Or so I thought. Here's the ignorant part. We only had one smoke detector installed in the house to begin with! It's in the master bedroom, and is hardwired. Good news - batteries. Bad news - no batteries. If the power goes out, we're in trouble.

So, I installed my new detectors upstairs and in the kitchen. I want to get a carbon monoxide detector for the bedroom, so I'll just get a combination unit, battery-powered, so we have all our bases covered in that room.

How in the world did I miss all this?