A self-hating Jew is a Jewish person who feels bad about being Jewish and might hate themselves for it. It's like if you really loved dinosaurs but then one day you started feeling like you shouldn't like them anymore and you started feeling bad and maybe even started telling yourself that you hate them.
Sometimes, people who feel this way might start feeling like they don't belong or they're not good enough or they might even start trying to hide that they're Jewish. They might start feeling embarrassed or ashamed about being Jewish and might try to avoid talking about it or showing it.
It's important to remember that everyone has different feelings and experiences, and it's okay to feel different things. It's important to try and be accepting and understanding of ourselves and others, even if we don't always agree or understand why someone might feel a certain way.