The star received his first Oscar nomination earlier this month (Jan10) for his role in Kathryn Bigelow's war film.
But the 39 year old can still recall playing with make-up pallets and mascara as a struggling actor - before his role as a U.S. Army soldier skyrocketed him to international fame.
He explains, "Instead of waiting tables I got to put make-up on gals, so that was kind of nice.
"I didn't know how to do make-up at the time. I convinced the ladies at the counter - I said, 'Why is it that you guys are wearing makeup? Maybe you want a guy's opinion (on how) to put on your make-up.'"