This playful quote reflects the dynamics of a relationship with a sense of humor and affection. In the first part, the speaker expresses a sense of wonder and perhaps self-doubt, contemplating how the other person can tolerate or "put up with" them.
However, the tone shifts in the second part as the speaker playfully remembers that they, too, have their quirks or idiosyncrasies that the other person accommodates. This realization leads to a sense of equality and balance in the relationship: "so we're even."
Overall, this quote highlights the idea that in a healthy and loving relationship, both individuals accept each other with all their imperfections and idiosyncrasies. It's a lighthearted way of acknowledging the mutual understanding and acceptance that underpin a strong connection.