Lyrically I think the song is fairly self-explanatory, in terms of accepting partial responsibility for a relationship breaking down, but the first line sticks out the me the most "Is Mercury in retrograde or is that the excuse that I've always made?".
When Mercury is in retrograde, it is a time of inner reflection and re-evaluation, which is a main theme of this song and the album as a whole. The writing process of the album was from the end of 2012 to mid 2013, and the final Mercury retrograde of 2012 was in the time where Scorpio was the ruling sign (Katy's sun sign, in this time she and other water signs would be more reflective than non-scorpios) and the first Mercury retrograde of 2013 was when Pisces was ruling (another water sign like Scorpio, also more reflective than non-water signs during this time). I believe these retrogrades would be particularly influential to the album's lyrical content, particularly for a Scorpio (which she is)
Lyrically I think the song is fairly self-explanatory, in terms of accepting partial responsibility for a relationship breaking down, but the first line sticks out the me the most "Is Mercury in retrograde or is that the excuse that I've always made?". When Mercury is in retrograde, it is a time of inner reflection and re-evaluation, which is a main theme of this song and the album as a whole. The writing process of the album was from the end of 2012 to mid 2013, and the final Mercury retrograde of 2012 was in the time where Scorpio was the ruling sign (Katy's sun sign, in this time she and other water signs would be more reflective than non-scorpios) and the first Mercury retrograde of 2013 was when Pisces was ruling (another water sign like Scorpio, also more reflective than non-water signs during this time). I believe these retrogrades would be particularly influential to the album's lyrical content, particularly for a Scorpio (which she is)