Why is it said that where Saturn falls in one's chart, that area will become a hindrance in the personality?

* I go for the "area that needs work" school of thought. Mine is in Virgo in the 6th. Never been a problem with health till this latest Saturn return when diabetes came along with Saturn. And that disease is all about restriction and structure. It also is squared by my Venus, the real hindrance in my chart. Makes me feel unloved and unlovable, makes me inept in social situations, and unworthy of good things. Saturn is a hard task master, but when I can allow myself to accept good things and just say thank you, I feel so accomplished!