I think some actors fall into the role, with raw talent that they later perfect by going to acting workshops. For example, if I recall correctly, Wentworth Miller, the actor who played Michael Scofield in Prison Break was actually a college student when he was "found" and started modeling. One thing led to another and eventually he landed a small acting gig. After that, to better perfect his acting, he went to school for it. Some time later, he landed the lead in Prison Break and although the series has ended, he definitely showed that he can act and I doubt will have any problem finding another lead role.
