I've read the book and it's an amazing read, both for details of what occurs in the camps, and for the issues Shin faces trying to assimilate in both South Korea and the U.S. Beyond symptoms much like PTSD, he has perverse difficulties with money and personal finance. At the same time as he expects to be cared for in a bare way (because the camp existed to give him a really shitty place to sleep and really shitty food), he's deeply suspicious of any largesse shown to him--it's either a bribe requiring action, or an unexpected windfall that he must consume immediately to avoid it being taken away from him by a stronger inmate, or the possession of which might be grounds for further punishment. He has trouble saving money or conceiving of budgeting his money. He has trouble planning beyond a few days in the future because, in the camps, nothing was in his control, so planning was not just immaterial, it was counterproductive and risky.