Nedarim 30: Tricky Vows

Unfortunately today's daf will receive only a cursory review, due to my own poor time management skills. 

The gist of today's daf is that people make bizarre vows, and sometimes those vows will stick.  If a person says that he will not benefit from anyone who's skin sees the sun, he will not benefit from almost anybody.  Even the skin of people who are blind sees the sun.  

If a person makes a vow regarding people with blackened heads, to what is he referring?  Children, who do not cover their heads?  Women always cover their heads.  Could it be that men only cover their heads sometimes, and thus this is referring to men?

What is interesting to me about this daf is:

1) the rabbis understand that people can vow about anything, and it is their job to figure out how those vows might play out
2) in examining one of these bizarre questions, the rabbis come up against something that is actually fascinating.  Who's head is blackened?  What do we learn about society based on that statement?  What do we learn about halacha based on that statement?  

Sometimes it feels as though the Talmud is a treasure map - with many, many treasures - and it is our job to figure out what is metaphor, what is pshat, and what is something else entirely.