Mom would sprinkle a few drops of dish soap onto our plastic slide, hook up the hose, and away we’d go. Dad would swoop us up at the other side, and we’d run towards Mom, ready for another go-round. Soon, more neighbor kids would hear us, and they would slide with us down the slippery slope. It’s easy to slide downhill, however, trying to reverse course is next to impossible after reaching the mid-point because momentum kicks in. …