Our lawn sprinkler has always given us trouble. My husband tells me it has something to do with the manifolds, the things that have electrical wires connecting the faucet to the valves that control each sprinkler station. I guess if it weren’t for a faulty manifold though, we would not have discovered until much later that my father-in-law, Danny, had Alzheimer’s. Danny was a licensed electrician. Before retirement, he worked for Fort Monmouth Army base in New Jersey. When my husband and I were first married, Danny helped us renovate our 80-year-old fixer-upper in Red Bank, N.J. He was so handy. He helped Peter install 18 windows in our home over one long weekend. We installed a brand-new bathroom together. So when Danny and his wife, Mary, came from New Jersey to visit us in California for a few weeks many years later, we assembled our fix-it list. Right at the top was the sprinkler system. Soon after father and son got to work on that troublesome manifold, my husband came...