Zac Efron was a "geek" at school.
The 'High School Musical' hunk - who has been dating co-star Vanessa Hudgens since 2005 - admitted he wasn't always a success with the ladies, and was actually a "late bloomer".
He said: "I wasn't a heartthrob at school, I was a geek. I was a gawky 17 year old, a lanky, skinny, awkward kid. I was definitely a late bloomer."
However, the 22-year-old star revealed he often experiences "over-physical" fans and on one occasion returned from a premiere to find a fingernail stuck in his back after fans came rushing at him from every direction.
He explained: "There's no guidebook to adulation! When the fans get over-physical and emotional, I just say, 'It's very nice to meet you, calm down'.
"One time at a premiere, there was a huge crowd that got a little bit out of control. A barrier broke, fans came rushing over and I was pulled in every direction. Later that night, I took off my shirt and there was literally a fingernail stuck into my back."