How do I stop feeling quilts about possibly putting my two weeks in?

I possibly have a new opportunity at a place that would be perfect for me and in a field of work I’ve always wanted to work in but somehow I still feel so guilty leaving my current job if I get this new job. My current job took a chance with me and has been sooo understanding and a great place to work and I run one of their departments. Why do so many people feel guilty leaving their job when they’d be happier somewhere else? It’s a struggle