It's that I'm not the first one to be making these dumb mistakes. :)
Every single time that I've been stumped by some odd error message or unexpected behavior in a program and then Google it, the first (and sometime the first several) listings are all on StackOverflow. Many of the answers help (some don't) but nearly every time, I see some other purportedly skilled programmer has had the same exact problem that I'm having. Or this problem.