Denial?

Hi, I am a former Catholic, now Non Denominational Christian who just went to Apostolic Pentecostal church service for the first time. My friend joined the church a year or two ago and has been wanting me to go, so I tried it. It was definitely an experience. Nothing like anything I am used to. My question is, there are lots of things he used to do that he is now completely against.

Used to: - wear shorts/ tshirts, now he doesn’t. Even when it’s blazing hot out. I know the women are generally required to wear dresses but didn’t realize men have a code as well? - get tattoos, had piercings. Now he doesn’t. And is against it pretty heavily. - watch tv, now he might occasionally watch a movie on a phone. - only really speaks to people he attends church with - of course the obvious, no cussing, drinking or anything like that

That’s all I can really think of at the moment. When it gets brought up, he acts like he’s always felt this way/ had these opinions. When I try to ask if it’s something new he believes based on his new found religion he will deny heavily. What is up with that? Is this the same for anyone else? No hate at all to him or anyone I’m just genuinely curious.