Whether because Jews are matriarchal or by pure coincidence, I can trace my lineage really well on both my father's matriarchal line and my mothers, but not the patriarchal lines. In the case of my mother's, the Epstein line, it goes back to my grandmother being the oldest of practically a baker's dozen of siblings, almost all of whom went on to be fruitful and multiply. In the case of my Dad's his mother, a Rosenburg, was the youngest of nine. With people divorcing and remarrying, sets of siblings that span 20 years, everyone reproducing and friends of the family that are so close we don't even define them as unrelated, leads to a huge, sprawling crazy family tree. The especially nutty thing about the Rosenburgs is that everyone had fallen out of touch for years and then all of a sudden I find out through pure happenstance that my father-in-law works with one of my lost cousins (or father's cousin's son to be exact). This was even more amazing considering Rosenburg is an ersatz last name, so the chances of finding a Rosenburg who was related to me are vanishingly small.