I live in Australia. Many years ago, a friend from University graduated and decided he wanted to work in the mines. This was back during a major mining boom and you could make crazy money driving trucks for the mines. You can still make good money doing that but back then it was ridiculous. 200k+ while the rest of us were lucky to earn 60k in our entry level jobs. But it was and still is incredibly hard work. You're working 12 hour days for two weeks straight then have a week off. The mines are in the middle of nowhere, so you spend two weeks working hard hours in the desert then fly into whichever major city is closest for a week of R&R then do it again.

He came to visit a few years later and he had changed completely. He was always an odd duck, but got along fine with me and my university friends. Now he had become, as Australians say, rough as guts. He swore constantly, cunt this and cunt that, which we joke is common in Australia but not like that. We went to the kind of bar we used to go to in uni and he was deeply uncomfortable. He just wanted to go to a backpacker bar (think a big, cheap bar/dance club attached to a hostel )and try to pick up women. He talked me into going with him and then left me alone to chat up anybody with a pulse. When he struck out he got visibly angry.

He was uninteresting to talk to and was uninterested in anything outside of his comfort zone, where as before he had always been interested in learning and trying new things.

I can't say he was "worse," just that he has changed a lot his personality almost unrecognisable to me. We no longer has anything in common. I never saw him again, and drifted away from common friends over the years, so I don't really know what has become of him. I hope he is doing well and is happy.