If you restart the computer, it actually restarts it.
I don't know why you shut it down and then power it back on...
I rarely ever turn off the computer. I sleep 95% of the time. If I am going away for a few days, then I shut down to prevent kids from easily using machine or from wandering cats on keyboards. If I had issues with something and I wanted a cold boot, I did a shutdown, not knowing that is NOT what I was doing.
Its troubleshooting mode or hardware changes that gave me a lot of grief with fast startup.