Am I crazy? I reallllyy dislike my coworker

I really need to know if I’m crazy or not…

Ok so for some background I work for a very small government agency, and for all intensive purposes we operate largely as a non profit. I’m just starting my career. This is my first full time job out of college. I work for an awesome team, with the most amazing supervisor and two other coworkers I really love. When I was hired I was genuinely elated to be joining this team. But when I started things changed. It turns out after I was hired a senior staff member decided they wanted to be a sahm and so they hired another person after me. He started 2 weeks after I did and he is quite literally the complete opposite of me, professionally and otherwise. But here’s the kicker: we were hired for the exact same job, with the same job title, working the same hours with the same job duties in the same office. He only makes a dollar more an hour despite him being 45 years older, with 3 more advanced degrees and quite literally 45 years more of work experience than me. I knew it was going to be bad when on his FIRST DAY he said how grateful he was for this job so he could no longer be living in poverty, but then the next day when he chooses to take a very personal call to the IRA account manager in our shared office, I hear him listing his assets which included 3 million in his bank account, an additional 2 million in investments, the home and 15 acres of land he owns (outright) and a fully funded retirement account with almost 2 million in it. Now I don’t know much, but that does not sound like poverty to me.

Sure as a recent college grad with insurmountable debt, and nothing but $200 to my name, that probably enraged me a little more than it should, but I definitely tried to give him the benefit of the doubt. But it didn’t stop there: over the last course of the year he has been the laziest mf in the office. He spends hours on excel trying to solve problems that don’t exist with spreadsheets and reading random articles while I have taken on 20.2x (yes I can also run a little excel function) the number of cases. The list goes on and on of reasons I truly dislike him.

Maybe we just have different approaches, maybe the different generations that we were born in make us unable to relate to eachother, but am I crazy? I need an unbiased opinion in my life.