Basically you realized you're not young anymore. It's 99% psychological on the real. Your life expectations just adjust. You start looking at the world different. I've had old heads tell me about it when I was 17, but I thought I was invincible back then and it'd never happen to me
Now I'm understanding my own mortality, so I'm a lot more cautious in the shyt I used to do.
ehhh, i think people who fear 30, are the same ones who dont have their life in order, and haven't accomplished what they set out to do before they hit 30.