Should a married woman cover her hair when she's alone at home?
Now this is already a question in Halacha, and we have a principle not to answer, however I will go out of my geder today and say something about it. The gemara talks about a certain woman, who had five sons kohanim gedolim. So they asked her, what did she do that she was worthy of such a great honor? Five sons were kohanim gedolim!
And she said, the ceiling of my home never saw my hair, which means her hair was always covered in the house. Which means, if nobody is around she could uncover her hair, but she didn't, because Somebody was around. She was always aware of Hakadosh Baruch Hu, and this awareness made her bashful to uncover her hair.
That's why the Jewish nation has a practice when you have to dress and undress even though it's in a dark room, and you're all alone, you try to cover up as much as possible. Because, like it says in the Shulchan Aruch, nobody should say it's dark and I'm b'chadrei chadorim, and mi roini, who sees me in this inside chamber? Halo Hashem melo kol ha'aretz k'vodo, He's everywhere, and the more you train yourself to realize that, the more you are deemed worthy by Hakadosh Baruch Hu for great honor.
And although it's not a duty, but if a person has that feeling at all times, to be aware of Hakadosh Baruch Hu, then you're doing something that's very worthwhile
This word combines two meanings, Nezer means a "crown", and thus we see that "the crown of his God is upon his head" (6:7), similar to the word Zer which denotes an elevated border around some object, as the "golden border" (Shmos 25:11) of the Holy Ark of Testimony. But Nazir means also "one that is separated", such as in the verse Nazoru ("they withdrew backward") (Yeshaiah 1:4), similar to the word Zar ("a stranger"). These two meanings of the word Nazir thus demonstrate the virtue of the man that withdraws from the pleasure of wine and separates himself in spirit from all others that indulge in the pleasure of drinking; and therefore Hashem rewards this man with the crown of Hashem's favor.
But it could mean also that because a man assumed the "crown of his G-d" upon his head by devoting part of his life to thinking about Hashem, therefore he must abstain from wine because inebriation or even indulging in unnecessary pleasures diverts the mind from thinking about Hashem.