Let's also say that heaven exists, and it's where you were before you began your first life on earth, and it's where you will be after your last. It's very much like life right now, or even in the future, with all the conveniences and luxury items that humanity will ever feel they "need."
Before you began life on earth, God said that you could pick one thing that you would never have to live without, no matter what your hardships were.
What was your answer?
ETA: This is an item that you would never have to live without in any of your lives. So if you couldn't live without your electric toaster, then you would begin life on earth after the invention of the electric toaster.
ETA 2: Okay, okay, we're talking material objects here. And among those, luxury items. My fault for not specifying it, so those who caught me can keep your happiness. :p