No, thats not what Hoichi means. What he means is that once a con gets inside, their perspective changes completely, where the outsider who never experience may not understand or realize what is going on. Once one gets inside it stays in them forever.
When one knew they got inside permanently (Lifers), the only thing that they longed the most is called Freedom, they will do anything to get out of the joint that they got stuck forever. This is something you, me, and others who never got stuck in jail may never understand fully. This is mainly why these two scumbags who just escaped from NY max prison just do it, even though more time will add on top of their "ALREADY MAXED" sentence. What more they got to lose when they have the opportunity of freedom once again?
