After three months of training, his way of thinking was completely re-programmed.

re-programmed 是动词 re-program 的过去分词形式，表示被动含义。re-program 由前缀 re-（表示"重新"）和动词 program（编程、设定）组成，字面意思是"重新编程"，引申为"彻底改变、重塑"。 在句中表示"被重新编程/被彻底改变"的意思。