I do agree that consumption is part of the equation, but I think your looking at the wrong sorts of consumption. Personal computers, personal usage of lights, disposable products use by individuals, for those most part these are a very very small portion of the consumption or the issue.
If we want to worry about the consumption side of the equation, as we should, then the places to focus would be mostly around shipping, fuel used by boats and planes to ship packages is by far the biggest part of that equation, to the point that the usage of your lights is irrelevant.
Also disposable products is a bit in the middle, depends on which products.. plastics for example are unusual as they are secondary products, so reducing your consumption of throw away plastic actually has no positive impact of any kind. But throwing away electronic devices is a bigger issue in that sense.
Yea, always good to evaluate your own contributions. But what I am saying is when you evaluate your contribution it shouldnt be the fact that you leave the lights on or drive an SUV that you should be considering. Instead consider how much stuff you guy that needs to be imported from overseas and reduce that as the priority, you will have a much bigger effect that way than you might be turning off your lights more often.