Some of this is Orthodox, some is culturally Jewish.
1. Even if you don't keep kosher, drinking milk with a meat dinner is slightly gross.
2. Shrimp are NOT kosher. Neither are Reuben sandwiches.
3. Single people do not bring dates to weddings. If they do (after asking if they can), everyone will assume there will be another wedding in the near future. Consequently, you don't see "and guest" on invitations.
4. "The Holidays" happen in the early fall.
5. Your mother makes the best chicken soup ever.