In my hometown we obey some values which build by old people that make our relationship better with each other and people live in harmony. Among all of these values I think modesty and respect to the old people are two very impressive values.
Because we have a large population even in the old time. There will be a lot of people with different abilities and advantages. Even you are good at some thing but there must be someone else who is better at it. If you are so proud with yourself and look down on others. You will be defeat and being humiliated at last. From these reasons our ancestors find it is better to be more modest to avoid unexpected embarrassment and comfort people around you.
We think the old people are the basic of the society today and they grow us up. That's why even they get old and be less helpful to build the society we still need to take much more care of their lives. Every one will get old one day and no one want to be ignored and discriminated after you serve all you can to the society in the past days. So we not only show respect to the olds, but also make our lives better in the future. Also we have a proverb that" you should listen the old mans' word". As we think the experience and knowledge of them can give us a lot of help and good suggestions that benefit us a lot. This is another reason we treat old man so important.