Would I trade the time I spend playing with my grandkids for the fun partying days of my youth?Can I go back and forth in time?“No.” Okay, then, no, I wouldn’t trade time with my grandkids to be 40 years younger and single, free from most responsibilities other than waking up in the morning and going to work. In fact, looking back at all the pleasures I have experienced in life, going back even to my own childhood, playing with my grandkids ranks numero uno. Nothing can compare.I have a friend… “Only one?” As I was saying, I have a ...