Yeah but they have more knowledge and life experiences. For example. Let's say you are 20 years old. Do you think you know more at 20 than you did at 10? You should, because you have grown 10 years and there was a lot to learn and experience in that time. Now let's say you are 30. Do you think you will know more at 30 than you did at 20? Of course, because you have grown 10 years and there is even more stuff to learn and experience then you could possibly even imagine in the first 20 years. Now add another 10 years, and another, and another, and keep extrapolating that out and maybe you can imagine the knowledge and experience that a 60 year old has over a 20 year old. Maybe you don't see the knowledge of a 60 year old when you are 20 but it's just as powerful and valuable as the change you went through each decade prior.

Of course this doesn't apply to everyone because of a little thing called arrested development which can stifle growth. Some people stop learning at a certain age and become isolated and angry especially if their life did not turn out the way they hoped. And even if their life goes well some get intrenched in habits that got them through their early life and they are not going to change their view of the world. But for the majority of people that grow old life will force them to learn and adapt and compromise and grow in such a way that they are some of the most gifted, knowledgeable, and understanding people you will ever meet.