As we have seen in Massekhet Nedarim, it is essential that we understand the intent of the person when they accept a vow upon themselves. The Mishna on our daf teaches that if a person is offered a cup of wine and says, “I am a nazir from that,” we assume that he truly intends to accept nezirut. Nevertheless, the Mishna continues with a story about a woman who was drunk and refused another cup of wine, saying, “I am a nezira from that,” where the sages ruled that she was merely refusing that drink, but she was not accepting nezirut on herself. The Gemara explains that the Mishna is essentially teaching that we must distinguish between cases where the person’s intent must be assumed to have the standard meaning, and cases where circumstantial evidence points to a different interpretation.
Clearly, the point that the Mishna is making is that a person who has drunk enough to recognize that he should not be drinking more may “swear off” another drink, but we cannot assume that he is accepting true nezirut. Should a person be drunk enough to have lost control of his senses – in the language of the Gemara, “as drunk as Lot” – his statements will not be taken seriously in any case.
There is a variant reading of the Mishna that has the woman who refuses the drink shekula – bereaved – rather than shikkora – intoxicated. This appears to be the reading that the Rambam had both in his Commentary on the Mishna and in his Mishne Torah where he rules (Sefer Hafla’ah Nezirut 1:11) that a person who is in mourning or in a state of bitterness, who refuses a cup of wine that is offered to him by his comforters saying, “I am a nazir from that cup” will not be considered a nazir, and will only be prohibited from drinking that particular cup. This explanation helps clarify why the Mishna brought an example of a woman who refuses to drink (it is difficult to imagine why the Mishna would choose as an example the unusual case of a drunk woman, but we can well understand the case of a grieving woman.)