Due to the fact that Thais can change there first Names any time they want (also in there ID Card), you can encounter that a Person has many Names. For example, if somebody suffered from a long illness, it might be supposed that the first Name caused bad luck and so they change it. Then about Nicknames: everybody has many different groups in his/her life, like family, school-friends, university-friends, colleagues, sport-club friends etc. It can happen that any of these groups might call the Persone with a different Nickname not even knowing what there real Nickname is, given by the family. For example: my wife has changed her first Name once in the Past and has 3 Nicknames, so she has 5 Names, I beat you by one