Why Am I Invincible?

I traveled through time and was an ordinary person for many years. I was bored playing with ants and hunting game every day in my mountain nest. Suddenly one day, I realized that I was invincible! The outside world is very exciting, and the people outside are indeed very sophisticated, but it doesn't matter, hard fists are the truth! You are not convinced! I will beat you until you are convinced! ! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.