There should be a power button and when you press it, it should turn on. Except when it's an HP computer, the chances of an HP computer turning on when you press the power button is 10 times lower than a regular computer.
My 4AM ritual: get laptop from bag and plug in power, press the button with left hand while run to kitchen in my right to get a snack. Pour drink then run back to login. Get solid snack/food then run back and open firefox (except if it was on hibernate then all is well).