The phrase should be punctuated as follows: "...said he had done things he hadn't, tried to be something he wasn't,..." = He had said that he had done things that he in fact had not done; also, he had tried to be something that he was not. The difference is with the comma between "hadn't" and "tried"

hi, according to the part which follows word 'like', it is clear that men can not do things in the field they are not involved in, or we may say, if you do not belong to that filed or area, you can not do things which is specific to that field or area. and go back to your question, the man is interviewed in certain field, he said he had done something specific to that field, but in fact, he never involved in that filed before. In conclusion, we may say, one had done something in the field he had never involved in. So, what he said is a lie.