Remember that Friends elevator where they killed off Joey’s character because he claimed he wrote his own lines.
If you’re Michael Caine, you can apparently get away with it.
“”I always make up my own back stories for my characters,” says Michael Caine. “Nobody cares but me, but I do it anyway. And my backstory for Alfred was that he was with the Special Infantry Service – sort of like the Navy SEALs during World War II. But he got injured. In order to stay in the service he took a job in the officers’ mess as a barman … You see, you’re not dealing with an ordinary butler here…”
From Frank Miller’s 1987 Batman Year One, where truth be told they’ve stolen (smartly I might add) the whole new Batman experience from.
“If I ring this bell Alfred will come. He can stop the bleeding in time. Another of your gifts for me father. I have wealth. The family manor rests above huge cave that will be a perfect headquarters. Even a butler with training in combat medicine. “