“’Til death do us part,” huh? Whoever wrote those words couldn’t have meant physical death, could he? Surely that refers to death of a dream. The end of compatibility. Irreconcilable differences about where to spend our vacation. After more than 35 years in the same canoe with a man who is in some ways my polar opposite, I’ve logged a few travel miles, not all of them smooth sailing. Have I learned anything that might keep other couples like us from capsizing?