With age comes wisdom, and a lot of mistakes lead up to getting to a ripe old age to have that wisdom.
Even as old as I am I still remember to always be a student (it is the mindset) and no matter the age of the teacher there are always new lessons to be learned in life.
Treasure those who pass on the learning and never toss the old to the curb for they have lived a life of learning to share.
Once they are gone so goes all that wisdom...