I think I wasted my grandfathers heritage and life lessons.
Why do you think you wasted your grandfather's heritage?
I was merely an ignorant jerk who didn't know any better
It is hard when you are young to know what to do in life but it is not good to waste your time on things that are not good. You won't get that time back and it will hurt your future.
I think I'm going to cut my loses and change my life around.
It's better late than never. You can learn from your mistakes and don't make the same ones again.