If I'm going to wake up a computer whose monitor is dark, I typically hit the super key, arrow keys, or sometimes the space bar and would never hit Enter as the first key. Why? I remember when people used to just turn monitors off manually before monitor power management, and I remember blank screen savers with first gen energy saving monitors that would turn off if they detected a blank screen. It only takes once where the monitor is off and you hit a key to turn it back on and accidentally confirm some dialog or accept changes or execute a command before you start using keys that don't actually do anything.