I'm not sure how the discussion went from art to power supplies, but... Turning off a computer doesn't completely turn it off. Specifically, ATX power supplies

I'm not sure how the discussion went from art to power supplies, but... Turning off a computer doesn't completely turn it off. Specifically, ATX power supplies have a standby +5V output, even when the computer is off. (This is how Wake-on-LAN works, for instance.) So it's quite possible that you needed to disconnect the computer to get it to fully restart. As far as discharging capacitors, that's an issue if you turn the computer off and on rapidly; the power supply can continue supplying power for a few seconds due to its capacitors, so the system might continue uninterrupted.