What were you doing in September of 2015? Were you mourning the end of summer, always gone too soon? Adding to your already considerable collection of wool sweaters? Tweeting nonstop about how stoked you were for PSL season? All of the above?Well, while you were busy doing that, you failed to notice one subtle change that supposedly went down sometime during those 30 days. According to Hollywood Life , September 2015 is when astute fans first started noticing that Katy Perry had gone and gotten herself a gold tooth.Sounds kind of ridiculous, right? But the evidence is undeniable. If you pay a bit more attention to the goings-on of Perry's smile in photos from the past year, you will indeed find that one of her teeth (upper-left-side canine, to be exact) is adorned with a gold detail that sure looks a lot like a Nike swoosh. Seriously.We took it upon ourselves to do a little bit of investigative research and dug up this photo from — you guessed it — September 2015. It’s all true: the gold tooth, the swoosh, the fact that Perry's superfans have known all this time. The only question remaining is, how did we miss this?