While nick names are certainly a part of American culture, they are no where near as widespread or common as in Thailand. Everyone has a nickname and some have several. The parents usually give their children a nickname when they are babies, and those nicknames are used throughout their lives.
Take my wife for example. Her given name is Pawaree, but her nickname is Tim. The only time that she really uses Pawaree is on legal documents.
Of course the name Tim can cause quite a bit of confusion in the U.S. where Tim is nearly exclusively a male name. I was practicing law with a large law firm with several offices when Tim and I got married. Before leaving for our honeymoon, I sent out an email to my office's distribution list thanking everyone for their kind words of support for Tim and my marriage. Well, what I didn't know was that the distribution list included some people from our Louisville and Lexington branches. When I got back, Rick, our office manager, told me how he had gotten calls from both offices. They had assumed that Tim was a guy, and were surprised at how the Covington office was so open about such a relationship. Rick laughed and explained to them, that I was indeed not gay. Not that their is anything wrong with that.
What made me think of the nickname story is that I was eating lunch with Tim today and one of her employees came into the room. She asked him if he had eaten, and he responded that he had "eaten rice with banana". She thought that was funny and asked him if he had really eaten rice and banana. The other girls laughed because what he had actually meant that he had already eaten rice with their co-worker named banana (gloy).
Banana isn't even the most unusual nickname. Tim has cousins, "A", "B" and "C". She has another cousin named Sweet. Some might find her parents choice to nick name their children Top, Tip and Tim worthy of a light chuckle. I have a nieces named Nudee and Pinkie. I've heard people with the nickname shrimp and dog. Really most any moniker is fair game in the Thai nickname game.
I'm glad that we don't name our kids after food in the U.S. "Hey mom, Pizza, Pickles and I are running over to Club Sandwich's house." "Okay Ketsup, make sure you are back for dinner, Uncle Turnover is bringing over Saccharin".