Thats the whole point? If Paula Radcliffe (random I know) hadn't bottled the marathron in Athens when she was the World Champion at the Marathron for the past few years she'd of won a gold medal, but she didn't.
If Italy knew how to take penalties we wouldn't of went out in France 98 because the last penalty hit the crossbar, if England didn't bottle every penalty shoot-out ever they might actually of won a world cup in the last 50 years. The point is they do miss them, thats what makes a bottler a bottler.