It is not always defined by the number of hours worked. Many young professionals put in long hours at work. But many of them also struggle to have a balanced life. If you've learned to live a balanced life, you have something to teach them. Employers look for something more from experienced workers.
Wisdom involves using past experience to help solve a current situation.
Having successfully survived difficult situations, older workers can apply their knowledge and experience to make better judgments than a young person might make. Wisdom also means keeping an open mind to better or more appropriate ways to solve a problem. The other day, I was reminded of the stereotypical differences between youthful and seasoned employees when I overheard two conversations on a university campus. A young student giving a passionate discourse on a current societal problem suggested a rather naive solution that seemed to me to have come from a textbook. I got the distinct impression from the speaker's tone of voice that the problem was going to be addressed in the same manner as it had been for years.