How do I humble myself?

In the past year or two I’ve noticed that I’ve been a little stuck up. The way I talk to people and the things I say are a little condescending. I don’t remember being like this when I was younger but now that I’m older I’ve graduated and got myself a good job at a big tech company. At work, I mix with people who are primarily private school educated and I’m from a difficult working class environment. So perhaps the fact that I did as well as or better than people who had everything planned for them, has gotten to my head. I’m still humble in comparison to those rich kids but when I speak to my friends from home I come across really cocky. It’s difficult to talk about things like work or whatever without accidentally mentioning some perk that comes with my kind of job. Other times I feel somewhat annoyed at my friends because I genuinely consider them dumber than me and the things they talk about sound so irrelevant/stupid/obnoxious. They often spend their time discussing horoscopes or conspiracy theories and are the type of people who have can’t hold down a job, did badly at school, have horrible planning skills etc. So the fact that they preoccupy themselves with all these topics makes me annoyed and often I call them out for believing in certain things, as if I know better than them. Even they have remarked that I’ve changed. I used to be much nicer. How do I humble myself? How do I not feel like I’m in a room full of idiots?
How do I humble myself?
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