To give you an idea of what I mean, consider something Paul Krugman says in The Accidental Theorist, p 58: "At the end of the 1983 to 1989 recovery, the bottom quintile was still worse off than it was in 1979." Or, for a more recent and broader example, in the introduction to The New Geography of Jobs, Enrico Moretti says "for the first time in American history, the average worker has not experienced an improvement in the standard of living compared to the previous generation. In fact he is worse off by almost every measure." (I still recommend both books, by the way.)
It's true that if you use particular measures, compute the numbers in certain ways, and kind of squint while looking at them, in low light, you can indeed get these readings.
I look at things differently.
The view Moretti and Krugman offer has a pretty clear implication: if I was offered the opportunity to go back in time to when my father was growing up, I should eagerly take it. (I'm assuming away issues such as taking those who are close to me back in time with me, for simplicity.) I am not now, nor have I ever been, a high income earner. So maybe to sweeten the deal, I could be offered a place back in time at a full quintile higher than the one my father occupied then, or I occupy now. If my standard of living is worse off by every measure now than a generation ago, I'd be a fool to not take that chance.
And I'd find myself living in a world where cars are heavy and slow and far less safe than they are today, and get terrible gas mileage and have no air conditioning. There would be about three television channels, and TVs would have tiny screens but still manage to be bulky and heavy. If I wanted to listen to music, forget about any kind of portable music player, and there certainly would not be one integrated into my cell phone. For that matter, forget about cell phones altogether. All my bills would be done through the mail - no home computers or internet. I could go on and on with such comparisons, but I'll outsource the rest of this to Louis CK:
So yeah...all this talk about how people like me have a "lower standard of living" than a generation ago...that doesn't pass the giggle test. The idea is so patently absurd that I'm more inclined to say that the numbers and measures people use to reach that conclusion have little practical relevance in the real world.