The gist of the article was how starkly different, to the point of seeming unresponsive and even barren, the world around you can seem when you leave a position of power. Obviously, the more powerful you are, the more you feel this literal draining and recession of the world.
The President of the United States is probably the most prominent example. In addition to having a channel and megaphone for any and every idea you have, if you want to communicate it, you also have ways of getting these ideas implemented, that you never had before and never will again.
You also have people waiting on your every need. Although Presidents including Obama frequently say how much they value their downtime and privacy, and that's true, the flip side is that when all you have is privacy, you miss being in the public light.
Possibly our world has changed to the point where a former President like Obama can continue to have some residual power, at least as far as people paying special attention to his ideas, if that's what he wants.
But my guess is Barack Obama will sorely miss even the onerous responsibilities of the Presidency, in ways the rest of us who have never been President or anything close to it can barely imagine. For that reason, in addition to all the extraordinary good he has done and tried to do for the country, I wish Barack Obama all the luck in the world.