Hanging on the wall in a restaurant was a painting of a stagecoach and horses crossing a river on the frontier. I remarked at what a hard life that must have been, but my friend disagreed. "Did they think that it was harder than we think our life is now?" he asked.
While I disagreed with him on his assessment, we did agree that people don't miss something before it exists. The frontier cowboys didn't miss microwaves or computers. My parents did not long for an iPad or 70" HD smart television. As I kid, I wasn't begging to be on a travel soccer team or to do 3D printing.
At times when I go to stores, I find myself desperately wanting something that I did not know even existed before I went shopping. People see things on social media that suddenly become a "must have." The whole advertising industry exists on this premise.
If you find yourself in this situation, take a moment to pause and realize that your life was good without it. Something may make your work or leisure easier/better/more pleasant with the addition of a new tool, but you were not missing it moments ago. The sensation of "lacking" is contrived in your head; it is a judgment you make for yourself.
Choose to appreciate your abundance rather than mourn for your lack of more.