I was told that in order to update a part of Steam that its auto-updater couldn't handle, I should run "sudo apt-get update" and "sudo apt-get upgrade". Well, I did, not realizing that the latter updates everything on my system to the latest build and that it would take over an hour. So I started doing other stuff while it ran, and then I accidentally closed the Konsole window along with everything else before it was finished. I don't know if it makes any difference that I was using Konsole instead of whatever terminal app Unity has, but either way, did I just ruin my computer?