Nobody ever demanded you unravel every mystery of the cosmos, or make sense of all you learn. There are things we will come to understand and things we will never fathom in our lifetimes—as well as things that are just beyond the gray matter within the human skull. As humans, we are indignant about such limitations, as though the unknown has no right to stay unknown. As though reality is defined by our ability to know it. It may be hard to concede, but none of us is G–d. Our job description is not to know all things. Our job...