The story that I have formed after reading the poem was a girl (around 13-15 years old) whom I presumed suffered from insomnia for the past several days. She met a boy whom she is familiar with (maybe a schoolmate from her former school or an old friend perhaps). The boy find her attractive so he asked for her number and eventually started courting her.
Days, weeks, and months have passed and the boy still kept on courting her. She then, finally gave her sweet “YES”.
That’s when the first three lines of the poem comes in.
The line All because you kissed me goodnight reflects the extreme and unexplained happiness that the girl felt when she finally accepted his love.
For the second stanza, she still feels exactly the same as with the first stanza however, the third line I couldn’t tell my left from my right signifies that she is not that sure if what she did was right or wrong. She only knew the fact that she is happily in love with the person she never thought would love her.