Many decades ago, during my time as a NASA Space Shuttle engineer, a co-worker couldn't locate a rogue unbalanced parenthesis in a complex program listing, in the days when computers, instead of identifying a particular syntax error, would print lame error messages like "Something went wrong." Worse, we wrote programs by punching 80-column cards -- no syntax highlighting, no color monitors.

My co-worker printed two paper listings, one with the error, one without, and asked me to count parentheses as he was doing, over a dozen pages. But because I knew this "superpower" trick, I laid out pairs of pages and crossed my eyes. A few seconds later I found and circled the error.

"Ta-daa!" I said. He never forgave me.