Put aircraft aside for a moment. Anyone ever needed to call some emergency services over the phone? Like police, or firefighters. I'll tell you, I use the phone every day, but the first time I needed to call the fire brigade for real - I couldn't do it. It's not that I was scared, I wasn't in any danger, and it was a small fire on a nearby roof, but I just couldn't dial the right number. I ended up trying three times, always pushing the wrong buttons, and trying again from the beginning, becouse I couln't rembember, at that moment, where the button that deletes just the last digit was!
And the thing is, you never know it it would happen to you, until you experience it! Overshooting the numbers? Hell, you'de be lucky if you remamber to bring the landing gear down ;)