Before I got Doctor Who, I went to the Guildhall School of Music and Drama. I went back to take the final grade exam, which is the grade you have to take before you can take the teacher’s diploma.

Sutton contrasts her formal, credential-based training with the career-defining break of being cast in Doctor Who. The remark highlights a common tension for young performers: pursuing structured conservatoire progression (exams, grades, teaching diplomas) while also chasing unpredictable professional opportunities. By noting she returned to complete a “final grade exam,” she frames her early acting life as pragmatic and disciplined rather than purely opportunistic—suggesting she kept a fallback path (teaching qualifications) even as television work began to open doors. The quote also implicitly underscores how major roles can interrupt or redirect conventional training routes, turning education into something fitted around employment rather than preceding it.