I (19m) am asking this because I seriously cannot wrap my head around why.

There are some people I meet, usually older than me, that are filled with dynamism and life and spark. They are usually very distinctive people with their own sense of style or behaviors. They feel like actual, real human beings that have a lot going on under the surface and are not afraid to be or do whatever the hell they feel like. This isn't even a money thing either, I just mean in their demeanor they are intensely themselves.

And then 90% of other people are shallow, placid born-for-nothings that seemingly have absolutely nothing going on behind their eyes.

What is your explanation or reason as to why some people seem to have this sense of dynamism and self determination, while others do not?