Behave. Millwall don't "hate" palace they laugh at you. Everyone laughs at you, and why is this? Firstly geography, stuck as you are in an unfashionable suburb surrounded by fried chicken shops and outlets where you can cable money to Bangladesh as easily as you can buy a copy of the sun. Your kit is ridiculous, your logo is shit and your ground is an eyesore, your chairman is a total tool and Kid Jensen is your spokesman...what on earth makes you think that anyone not actually born in Dulwich or Shirley Oaks would want to support you? You're a standing joke.
You missed out pretty much all the main reasons any genuine club would think they're an utter joke:
GOAL MUSIC (still can't quite believe this, any proper fan would be utterly fuming about this, would never EVER happen at the Albion)
Call and Response of the goalscorer's name (The most MLS, new-to-football thing you can do)
Half time BIRD SHOW (Words fail me.)