Everyday Spanish has a common way to report a mishap. The speaker does not say “I dropped the glass.” The speaker says se me cayó el vaso, literally “the glass fell, to me.” The same form gives se me olvidó (it slipped my mind), se me rompió (it broke on me) and se descompuso (it broke down).
In this construction the object is the subject of the sentence. The person appears only as the one it happened to. The form is common in everyday Spanish, in Mexico as elsewhere.