Growing up in a predominantly Jewish town, I learned some of the Jewish customs.  Here's a list of just a few I've become quite familiar with...

1. You prefer challah bread over whole wheat.

2. You refer to your friends grandparents as "bubbie and zadie."

3. You can recite prayers in Hebrew due to all of the bat/bar mitzvah services you've been to in your life.  Sometimes you may even be able to spot your friends' torah portion.

4. Your (second) favorite time of year is the High Holidays.  (Free feast, Jewish mothers and no school.)

5. You had your "summer friends," which were people you did country club sports with all summer while your school friends were at camp.

6. You're constantly being referred to as the "token goy."

7. You begged your parents to let you go to camp all summer and were very close to signing up for one of the many that have an Indian name (Tamarack, Tamakwa, Walden, Tanuga).

8. Your friends parents have "subtly" tried to convert you. 

9. Matzo Ball soup can always cure the common cold.

10. You call your friends parents by their first names. 

11. Most of your friends' last names end with berg, man, fried, baum, etc...

12. You've seen almost every episode of Curb Your Enthusiasm... because you've probably watched it with your friends' families.

13. Your parents already know you won't be home for dinner on a Friday because you'll most likely be attending shabbos at one of your friends.

14. You've read The Jewish News and know when one of your friends makes it in the newspaper.

15. You've debated going through your family tree to find some trace of Judaism in your heritage just so you can go on birth right (never works).

16. Mostly all of your friends single parents are on J-Date. 

17. Sometimes you refer to your friends by their Hebrew names rather than their real names.

18. You're no stranger to your schools Hillel.

19. Sometimes even months after meeting someone you'll hear "Wait you're not Jewish? Since when?"

20. You know whenever you go to your friends houses that their pantries will be fully stocked, thank you Jewish mommies!

21. You're no stranger to the terms "L'shana Tova," "Mazel Tov," "Shalom," and "L'chiam."

22. You're featured in your friends bat/bar mitzvah montage and probably wrote a ridiculous poem/song to sing to them.

23. You know your friends entire extended family due to all of the holidays and you have to hug each and every one of them rather than a normal handshake.

24. You have a collection of over 100 awkward photos from all the bat/bar mitzvah's you went to.

25. And you always wished that you could be thrown up in that chair

And you'd never trade your hometown for anywhere else!