When we were young and wild, my wife and I shared a toothbrush-- and this went on for over a decade; now that we're mature, we have our separate brushes (which made my students very happy . . . they were quite disgusted by the fact that we shared one brush for that many years) but I'm loath to admit that I'm not sure which brush is mine, so I use whichever one I grab first (there are four brushes in the cup, two purple and two blue) and so I'm going to check with my wife and see if she thinks that a particular brush is "hers" and report back to you . . . we might still be sharing a toothbrush afterall.