Remember the time when computer switches were somewhat like regular switches? A bit clunky, but you could tell which position was On and which one was Off.
Then, these switches got replaced by elliptical ones (I have this one on my work computer) and they look real cool, but they lost the important visual feedback–that on/off thingy. Both on and off positions look the same.
My computer at home has a circular switch now. Looks real nice. Press and release for switching on. Simple enough, I can learn that.
When the computer hangs though, how do I switch it off? Well, press the On/Off switch for a few seconds and keep depressed. This tells the computer to switch off. How do I find out if the computer has switched off. Well, if the monitor goes off, then I know. Oh okay, that I can somehow figure out. RTFM I guess.