A few days ago while editing some labels, I fatfingered something and I have no idea what. I have the blue bars at the top and bottom as pointed out by the arrows. They’ll squeeze down at times, but I don’t know why. Why are they? What do they do? How do I turn them off if I don’t need them?
Does this help?
Those lines means that you are in Envelope Mode, to be able to adjust the level of the tracks.
https://manual.audacityteam.org/man/envelope_tool.html
YES!! It’s off again. 
At least I know what it is, and how to turn it off. I’ll read up on it some more to understand what it does later. Maybe it’s something I could use.
Maybe it’s something I could use.
The envelope tool is very handy for level adjustments.