Oh it’s easy. I’ve worked at the same place since I was a teenager and never worked anywhere else in this field.

Lack of formal education is also an issue. No degree.

As for being good, I have a lot to learn, but I’ve consumed literally everything in my path for years. I literally live code. I code at work, I code at home. I’m humble enough to know I could grow by working in a team, and I don’t know everything, but it’s the only thing that makes sense to me - so I’ve done it, a lot.