When I tell others not involved in genealogy that I enjoy tracing my ancestors, they think that I am doing it for some narcissistic reason such as trying to prove I am a direct descendent of Queen Elizabeth the I or Attila the Hun, or some such nonsense. But they are way off the mark. Genealogy has allowed me to pursue some of my other passions - history, geography, sociology, and psychology. My attention tends to become scattered, but within the field of genealogy I can bring them all into line. History and geography need no explanation for genealogists.
Sociology is a little more subtle.
My ancestors came from a culture that existed in a different time and place than my own. Bits and pieces of that long ago culture still exist in my family's traditions. My mother tells stories from a past era, when life moved at a different pace. I have old letters written to my grandmother. In some way they sound quaint, but in another they reveal the same emotions we feel today.