The Holy Spirit is not leading us a merry dance.  One can not teach a child the intricacies of calculus when the child doesn't yet understand fractions.  The sum of human knowledge we possess in the 21st century is light years beyond what humanity understood in the first century.  For the Holy Spirit to insist all that accrued knowledge is meaningless would truly be leading humanity on a merry dance.  

Original ignorance is a much better explanation of original sin than some mysterious magical mark on our psyche passed on through sex.  We are truly born ignorant.  It is the community, beginning with our families, that is tasked with alleviating our ignorance and assuring our survival.  As to whether we got lucky and were born into a healthy family....or not, is one of those questions that demonstrates our ongoing ignorance of what life is really all about.