I am ashamed to say that my mind could not understand these 'mac behaviors'. in my mind, closing the shell does not mean 'shut down the machine (or make it stan

I am ashamed to say that my mind could not understand these 'mac behaviors'. in my mind, closing the shell does not mean 'shut down the machine (or make it standby). maybe i have a job running. maybe i am ssh'ed into it. likewise, when it is opened up, why does it un-standby or turn on? very confusing that the computer thinks it knows what i want; when i can push the power button to turn it on, or /sbin/shutdown -h now when i want it off.