Lower 25% in high school.
Went to art school, got bored, went on walkabout. ended up managing a comic book store...
Got a girl pregnant, got two more jobs working 65-80 hours a week, for around $22000

Bought a book on building your own computer.
Built it.
Got a helpdesk job
Worked my way up to sytems administrator...
Finally went back to school in Aug 2006 and have been a straight A student.
Motivation, perspective, and dilligence are the keys to success for me.
Not everybody is equally served by the standard school model.
It's a crappy fit for the way I learn, but what happened is I finally matured enough to take it by the horns and get what I wanted out of it.
OP, you may need to really figure out what you want before you're able to commit to it, IMO. Career counseling therapy might help you figure out what you want to do...