This quote by Aeschylus speaks to the concept that knowledge is not something that can be taught or discovered, however rather something that is acquired through experience. Suffering belongs of life, and it is through this suffering that we can get knowledge. It is not something that can be gotten through books or lectures, however rather through the challenges and battles of life. It is through these experiences that we can gain insight and understanding into the world around us. We can learn to value the great times and be much better gotten ready for the bad. Wisdom is something that is earned, not provided, and it is through suffering that we can get it.
"Raising children is an incredibly hard and risky business in which no cumulative wisdom is gained: each generation repeats the mistakes the previous one made"
"The man who makes everything that leads to happiness depends upon himself, and not upon other men, has adopted the very best plan for living happily. This is the man of moderation, the man of manly character and of wisdom"
