I think as we grow older we tend to make less mistakes. That is why older ones are mostly perceived as wise, due to the plethora of experiences they have. We learn from failure, and the wise ones make the mental note and decision to not make it next time since life is a series of related events.
Hence as we grow older we make fewer mistakes.
Listen to your elders, and learn from them, but know that not everything they advise is suitable as they advise it for today's world. But, in there somewhere, there is the core lesson.