Intriguing Bits of Genealogy

I find history and genealogy fascinating.  I was astounded, and delighted to find that my sister (and I) are eighth cousins of her husband.  My husband and I were twenty-third cousins.  When my sister brought Jim home (to Florida, from Colorado), my parents, sister and Jim went on a two week vacation, going to favorite beaches and the Everglades.  Everywhere they went, folks assumed that Jim was the son of my parents, and that Kathy was his lady friend. Jim looks/looked a lot like my father.  And we're related through families that were early immigrants to New England.
   In assisting another couple with their family trees, we discovered that I was related to the wife through my Mother's family, and to the husband through my father's family.  I happily call them both cousins, and we stay in touch.
   Earlier this week, I had to laugh out loud when I discovered another, unknown to me, family connection.  Mom is from Chincoteague Island in Virginia, and the families there married folks from nearby states and counties.  The Truitt family from Sussex County, Delaware and from Worcester County, Maryland has married into the family tree on Chincoteague many times.  Dad's family pretty much started out in New England, then hit Ohio, Indiana, Iowa, Kansas and Missouri.  I was filling in missing information on Dad's side of the family, when I stopped short and laughed. 
   My second-great-grandfather was Benjamin Nocks, and his brother was named William. Uncle William's second child, Lucy Alice (called Alice), married a man named Peter Truitt. In Indiana.  Peter Truitt's parents were born in Worcester County, Maryland. - And, yes, they are related to the Truitts who married into Mom's family in Virginia.
    That made me start thinking - is there a genetic trait, or subconscious stamp, that draws men and women together?  Here's a Nocks girl who marries a man who is one generation away from the watermen of the Eastern Shore in 1875.  Then, Dad, a Nocks Kansas farm boy joins the Navy, and gets sent to the Eastern Shore in 1947, where he meets and marries a waterman's daughter, with some of the same blood that his Aunt Alice married...
   I really have no clear idea - but it's something for me to ponder when my mind is otherwise disengaged....