No matter how focused we are on the present moment, we all have a past. Friends, relatives, photographs, songs, even smells can suddenly, unexpectedly, sometimes, unwillingly, take us on a journey into our past. Happy memories sustain us but difficult ones may overwhelm us. I can't avoid the fact that I have a past so I want to understand how I can stay present while I visit it. What does that mean for my body, heart, and mind?