Who could show us how to live better than a veteran happily married for seven decades? He says simple things we often take for granted are key to happiness. Old people’s advice usually strikes harder than others for they have seen and experienced life like nobody else has. Whether it is a 93-year-old man’s inspiring message to his younger self or a World War II veteran’s admiration for his wife, these wise words are worth remembering. Three things veteran considers important for a happy lifeAt 20, you may dream of an expensive smartphone. When you turn 30, investments and mortgages are all you…