I'm not disbelieving that Gene Hackman is your second cousin, Donuel, but as a rule second cousins are easily traced. One of your second cousin's parents is first cousin to one of your parents, and of course a first cousin has a parent who is a sibling of your parent.

It is far more difficult to trace more distant relatives. Although it can be done. I'll never forget the day that a man knocked at my door with a huge volume under his arm and subsequently showed me that we were fifth cousins. The Amish are notorious for keeping track of bloodlines.