No excuse, none? Not even the harried passengers at the terminal suddenly being told they need to check their carry-ons due to lack of overhead bin space, right

No excuse, none? Not even the harried passengers at the terminal suddenly being told they need to check their carry-ons due to lack of overhead bin space, right before they're about to board? You have never forgotten to pack something, or perhaps forgotten an important detail in a stressful situation?