What does experiencing anatta feel like?

I feel curious about what it actually feels like when someone directly experiences anatta. How do practitioners describe that experience? Is it sudden or gradual? Does it come with a sense of liberation, fear, or something else entirely? I’m especially interested in how this experience is understood or explained within different traditions, like Theravāda or Zen, if there are differences. Please note I'm not looking for just theoretical explanations. I’d really appreciate if there are descriptions from those who lived and felt experience of realizing anatta.