The 29-year-old sat down with PARADE magazine and dished about his less than perfect past: "I'm not Finn Hudson. I burned a lot of bridges, I was out of control."
Monteith dropped out of school -- after attending 12 different ones (including an alternative program for troubled teens) -- by the age of 16. He then entered rehab at 19 after his mother and friends feared he "could die" and demanded he make a change.
"That's when I first went to rehab," he said. "I did the stint but then went back to doing exactly what I left off doing." That was until he hit his low point, a time he refers to as "the crystallizing event."
"I stole a significant amount of money from a family member," he admits. "I knew I was going to get caught, but I was so desperate I didn't care. It was a cry for help. I was confronted and I said, 'Yeah, it was me.' It was the first honorable, truthful thing that had come out of my mouth in years."
He was given the option to clean up his act or his family would report him to the authorities. Monteith recalls, "I was done fighting myself, I finally said, 'I'm gonna start looking at my life and figure out why I'm doing this.'"
It was not long after that point where Monteith turned his attention to acting and after much hard work landed himself one of the most popular phenomenons on television. His reason for coming forward with his troubled past now?
"I don't want kids to think it's okay to drop out of school and get high, and they'll be famous actors, too. ... But for those people who might give up: Get real about what you want and go after it. If I can, anyone can."