First of all, Personal experience is essential for obtaining indelible knowledge. For instance, in an early age of our lives we were thought how to speak, to say please and thank you, things that never depart from us. This is knowledge that was learned from where our learning experience derived from, home, where our basic knowledge begins.
Second, the relationship among the people as well as friendship values is not taught by teachers in the classroom. Those relationships have known only by personal experience. Further, the young age people are not aware of love, these things you have to find out for yourself you cant learn them from somebody else.
Finally, some of the new technology and new things were discovered by personal experience and not classroom knowledge. For instance, todays popular phone was discovered by Alexander Graham bell. It was discovered accidentally.
Learning in the classroom although it has many benefits, all knowledge is not obtained from class because subjects are only taught by a teacher. But some lessons, which are pertaining to life, only will demonstrate by personal experiences. Every person should be learning more from real life than class room. I think real life is the best example for learning and obtaining knowledge. Once knowledge is gained by personal experience it is never loss.