It's probably a good idea...

to say "Happy Holidays" rather than "Merry Christmas" to these folks.

I sort of wish I could unlearn this:

Kabbalistic toilet paper

The Knesset correspondent of the ultra-Orthodox newspaper Hamodia, Zvi Rosen, relates that celebrated Hasidic admorim (sect leaders) would cut a year's supply of toilet paper for Sabbath use (to avoid tearing toilet paper on Sabbath) on this night [Christmas Eve]. Actually, this disrespectful act has profound kabbalistic significance, because kabbalistic literature extensively discusses Christianity as waste material excreted from the body of the Jewish people. Today, precut toilet paper for Sabbath use is available on the market; thus, the custom's relevance has diminished.

and this:

Abstaining from procreation

As was the case in 2000, Christmas Eve or Nitel Night this year falls on Friday night, and this fact has several significant ramifications. Because of this, certain acts that are desecrations of the Sabbath cannot be performed, such as cutting toilet paper or straightening out paperwork. Nor can one sleep throughout the entire Christmas Eve because of the obligation of eating the Friday night meal, although it is customary not to talk about sacred matters at the table when Christmas Eve falls on Friday night.

However, the biggest paradox concerns the procreation mitzvah (commandment). It is recommended that the commandment be observed on Friday night, which is a holy time. Yet on Nitel Night [Christmas Eve], which has no holiness, it is customary to refrain from observing the commandment, because of the fear that a Jewish child conceived on Jesus' birthday could become an apostate.

But isn't the precedent that if you are born on Christmas, not conceived on Christmas (Eve), that you'll become a really big apostate?