"In the current film, Titanic," joke

In the current film, Titanic, the character Rose is shown giving the
finger to Jack (another character).Many people who have seen the film,
question whether "giving the finger" was done around the time of the
Titanic disaster, or was it a more recent gesture invented by some defiant
seventh-grader. According to research, here's the true story:
Before the Battle of Agincourt in 1415, the French, anticipating victory
over the English, proposed to cut off the middle finger of all captured
English soldiers. Without the middle finger it would be impossible to draw
the renowned English longbow and therefore be incapable of fighting in the
future. This famous weapon was made of the native English Yew tree, and
the act of drawing the longbow was known as "plucking the yew" (or "pluck
yew").
Much to the bewilderment of the French, the English won a major upset and
began mocking the French by waved their middle fingers at the defeated
French, saying, "See, we can still pluck yew! "PLUCK YEW!"
Over the years some 'folk etymologies' have grown up around this symbolic
gesture. Since 'pluck yew' is rather difficult to say (like "pleasant
mother pheasant plucker", which is who you had to go to for the feathers
used on the arrows for the longbow), the difficult consonant cluster at the
beginning has gradually changed to a labiodental fricative 'F', and thus the
words often used in conjunction with the one-finger-salute are mistakenly
thought to have something to do with an intimate encounter. It is also
because of the pheasant feathers on the arrows that the symbolic gesture is
known as "giving the bird".
And yew all thought yew knew everything!