Because what others think of us becomes less important.

some can't run from society forever, I'll keep struttin

Mind over matter- overthinking too many things can halt so much potential. Labels never help people are constantly growing and changing as individuals. Who you were 10yrs ,3 months, 1week ago even yesterday can completely shift with the choices you take today . You can lapse back and forth between mindsets in societal behavior but you will always seek to find comfort and that's the ultimate key.

I think they are still shy. But age tells some that the persuit of happiness needs to act and not only to wait.

You grow some self confidence. You stop comparing yourself to others that much. You realize that people will always find something to criticise you no matter what you do, so why to care. And finally, you start understanding what the real problems are in your life. Others' opinion is not one of them. 🤷‍♀️

They stop caring about what others think because it really doesn’t matter

They are just acting, practising for acting class.