How has the money changed you?

Personally I don't think it's changed who I am but it's drastically changed how I live, and I'm older than the OP by a decade. The easiest way to conceptualize it when you're a college kid is that you drink cheap beer, cans of domestic crap, kegs, plastic half gallons of cheap vodka, etc. Maybe you can occasionally can afford better stuff or when the parents or friends parents are in town you'll drink good stuff so you know what it is but you're not buying it regularly. Then you get a job and realize you can afford craft beer regularly (in my day we called them microbrews-I'm not sure when that changed). But in general you're not ordering top notch single malts unless you're at a work dinner/expensing them, or your parents have money and they're paying. Maybe you occasionally order one that you're paying for but it's the exception. Then you work a few years, get a few bonuses/raises, promotions, move to new firms or whatever. And you realize that you can afford to regularly drink top shelf single malts and pay for them without a thought, and I'm not talking about the over the top $100+ ones, but you don't have a heart attack when you order a few $20-30 scotches/martinis. You also have developed a taste for wine and the lower end ones just don't do it for you and you can afford to spring for a nicer one so you do. Again, you're not necessarily downing bottles of first growth vintage Bordeaux on Tuesday nights but you're not ordering the cheapest bottles on the list. You're also less likely to be doing any of this regularly at dive bars or even loud bars where it's tough to get a seat, but at nicer restaurant bars. This can keep going if you make tons of money and I know guys who do regularly order first growth bordeaux and I know guys with tons of money who stay at a level where they don't blow money on $1500 bottles of wine on anywhere near a regular basis. And it doesn't mean you can't enjoy a PBR at a dive bar or a Bud at a summer bbq, but you're probably not doing that regularly because even when you host or attend a bbq, you have craft beers and decent wine.

You can basically apply this to many aspects of life. Housing: in college you were in dorms and crappy apartments. You graduated and got a job and got a better apartment, started making more and moved up the housing scale. Some guys top out and regardless of their comp or net worth figure that they don't need more than 4-5000 SF (in the burbs, I'm not talking NYC) and some try to compensate for the size of their phallus by replicating Versailles in Westchester County. Cars, vacations, watches, clothes and more fall into the drinking comparison. Having money is going to change what you do and buy, but it doesn't necessarily change who you are.

Most people who gradually make more money tend to not let the wheels fall off and let it drastically change them as people. Even thinking IB/PE, MBB, etc: to outsiders it may seem like you're making a ton at 25 or 30 but you're most likely living in an expensive city so it's not going very far and you gradually make more each year so by the time you're 35 or 40 you could be making seven figures (which is very difficult, takes a lot of hard work and luck and is by no means the norm even in finance) but you've worked up to it and it was gradual. You very well may be a douche bag but you probably were a douche bag when you were broke and 21 in college.

Where I've seen money change people is when they don't have much of it and then all of the sudden get a ton of it. When people are involved in a start up that exit relatively quickly, or they inherit money or quickly build a business and sell it for a lot of money or things along those lines is when I've seen it drastically change who they are. It's the money itself and if they earned it, through the start up route or building and exiting a business (essentially a start up, but start up has the connotation of tech) or I've even seen execs do an MBO where they were making a couple hundred grand before and exited relatively quickly to millions, they tend to think that they're the smartest and greatest person on the planet and everyone else is a peon that is far less of a being than they. I've seen good family men become whore mongers, cheat on their wives, do drugs when they never did before (nothing against drugs personally, but it's odd when a 40 or 45 year old guys who smoked pot a few times in college starts doing blow) and just generally treat people like shit when they would never have before.

None of this is hard and fast and are just based anecdotally on what I've seen.