Can you perform this small feat?

This passage hit me between the eyes during one of my studies:

"And which of you by being anxious can add a single hour to his span of life? If then you are not able to do as small a thing as that, why are you anxious about the rest?" Lk 12:25

In this part of Scripture, Jesus is talking about the normal cares of the world everyone has like food and shelter. But in the middle of this, He says that adding a single hour to one's life is a small feat!

Think about this for a minute. Over the years, mankind's put in innumerable years of work, study, and other resources into the medical arts, and yet with all that ongoing effort the best they've accomplished is a myriad of ways to help the body heal itself or provide aids to help it function properly. It has yet to figure out how to extend a person's life past the time when the body finally breaks down and stops working.

Yet here Jesus calls adding an hour to one's life a "small" thing.

I imagine if I was the author of all creation, of all the plants, animals, and people in it, then adding an hour to someone's life would be a small thing for me as well.