Both my children have 3 names as we all have had for many generations. We have a couple of traditions that seem to have lingered. The eldest daughter gets Grandma's maiden name and we try and choose fairly unusual first names with more ordinary second names...So I have Bryn Michael James and Kira Padraigin Stone...each name has a different story and the children love them. As have I with my name which is Imogen Veronica Cardle (can you tell which were the eldest girls :-)?).
It is entirely up to you how many names or what names you want. I wouldn't worry what other people think as long as you are happy with your choice.