It is quite possible that the beloved keeps their promise and arrives, but the real difficulty is whether I will be in my senses at that moment.

This couplet captures the delightful yet poignant irony of extreme longing. The lover acknowledges that the beloved might actually keep their promise and show up, but the real dilemma lies within himself. Waiting has driven him so deep into a state of emotional overwhelm and intoxication that he fears he won't be in his senses to truly live the moment.