Beyond books quote from Chanakya who has been considered as the pioneer of the field of economics and political science:

One whose knowledge is confined to books and whose wealth is in the possession of others can neither his knowledge nor wealth when the need for them arises.

– Chanakya Niti 39

This is so true. For example, if your wealth is control by your father or wife, you will not able to use it when required. Similarly, if your knowledge is restricted to books you will not able to provide good services to others. In other words practical knowledge is important to solve many complex problems of the life. Seneca the Younger, Roman Stoic philosopher, statesman, dramatist, put all this in a singe statement:

We learn not is school, but in life.