Knowing the naming convention can often help direct your family history research. For example, if your great grandparents named their first son John, you would know that John was quite probably the name of the father's father. Today, these naming conventions are not as frequently used, having given way to pop culture. Miley, for example, did not appear in the top 1000 girl's names until Miley Cyrus became a pop star and the name surged up to be the 127th most popular name in 2008. My own name of Ian was the 948th most popular boy's name in 1935 and today it is the 80th most popular name (based on U. S. statistics).
As I have suggested in earlier posts, finding ancestors can also be difficult because the name they were commonly known by might not have been their formal or registered name. My grandfather John Graham O'Neill used his middle name as his common name throughout his life. His brother-in-law Gerald Foley, from whom I receive my middle name, was not a Gerald at all which caused me many long hours of frustrating research before I discovered that he was born Louis Fitzgerald Foley. His name appears to be from his mother's father, Lewis Fitzgerald. Researching Uncle "Gerald's" brother Clarence Foley was even harder for Clarence was born William Dorsey Foley. Where he or his family derived Clarence I still don't know but he used that name rather than his given names throughout his life and is listed on many official documents, including his marriage registration, as Clarence.
Given names are important in researching family members as they point to your ancestral culture or the honouring of family members through namesakes but you need to be prepared for the mysteries as well. "A rose by any other name..."