The Button Nobody Could See

I spent three months watching people fail to click a button that was right in front of them. Not metaphorically. Literally watching. Coffee shop stakeouts. Screen recordings. The whole creepy surveillance routine. The button was large. Blue. Centered. Labeled "Continue." Nobody clicked it. Turns out they couldn't see it because they were holding their phones with both hands - one hand stabilizing, one thumb stretched to reach the next input field. The button sat in the visual blind spot created by their own thumb. Users thought the form was broken. They refreshed. They cursed. They left. I discovered this by accident when my phone battery died and I borrowed a coworker's ancient Android. The screen was cracked. My thumb covered half the display. Suddenly I understood why the analytics showed a 40% drop-off at that exact moment. The interface worked perfectly for right-handed developers testing on pristine devices. For everyone else, it was an invisible button. The fix wasn't moving the