Is there anything more disconcerting than a computer keyboard and mouse amok? For some reason just now my Bluetooth m...

Is there anything more disconcerting than a computer keyboard and mouse amok? For some reason just now my Bluetooth mouse and keyboard connected to the MacBook wouldn’t do what I want. Click an icon on the dock and instead of launching the app a Finder window opens with the Application I clicked highlighted. Click icons on the menu bar and nothing happens. Restarted several times, including without the externals and shutoff some items that start at login. It’s gone for now, but I don’t know which item I shut off was the culprit and I don’t know that I care.