Go to jail lol (not really). His worldview was an amalgamation of different periods spent in isolation in jail. When you have everything stripped away from you forcefully -like going to jail- it forces you to self reflect because you’re stuck in a box for most of the day the size of a walk-in closet with nothing else to do. 

Not only that, but the people you meet in jail all have stories to tell and a lot of knowledge can be gained from talking to other inmates, specifically inmates older than you. Talking to other inmates is also a way of maintaining your sanity, so people just sit around and talk about life, god, and play chess a lot. Jail forces you to face your innermost fears and develop courage as a means to just survive.

So essentially, this pressure can -in some cases- produce a diamond under the right circumstances.