A good way to make yourself feel your brain is broken and you no longer know how computers work is to sit down in front of someone else's machine and try to use it. It doesn't have to be running a different operating system. In fact, the closer it is to yours the worse and more confusing it will feel as you get tripped up by any of the dozens of things you feel are just how computers work but which in fact are some preference you set in 2004 (or 1984) and have taken for granted ever since.