I don't know why it is, but there seem to be so many differences. Some get up early Sunday morning and head out, some sit in front of their TV's. Some wear regular clothes, some get "all dolled up." Some even partake during the week!
And each one thinks, no, honestly believes that they are right. They will fight you, or at least argue with you about it. There have been countless cases of disturbances, and some of them between spouses, siblings, and other family members.
Then there are those who don't participate. Boy, do they catch an earfull! They are ridiculed for their stance by all the others.
Now, I have my own favorite, and I completely understand why someone would disagree with me, but I don't try to force my opinions on others so I don't expect it in return.