What's "my thing" mean and when's it used?

Native speaker’s answer
Rebecca
If something is "one's thing," it means that they like it. It's something that one enjoys. It could also be a notable characteristic or quality. So you can use it to say if you enjoy or don't enjoy something. Ex: Going out isn't really my thing. I prefer to stay at home. Ex: Ballet dancing is her thing. You should ask her to show you one of her moves. Ex: What's your thing? What do you like to do? Ex: Animations aren't my thing. They're too childish for me.