He has revealed that his childhood was marred by a serious illness, bacterial meningitis, before he discovered acting in his teenage years.

[1] Children's entertainment programmes such as Playschool were key to his recovery, which explains his continued passion for the industry.

Nicholson joined the Australian children's musical group Hi-5 in June 2007 when original member Tim Harding was injured in a serious motorcycle accident.

"[1] Nicholson filmed seven television seasons of Hi-5 and Hi-5 House, before announcing in August 2015 that he would be departing the group at the end of the year.

After Superdudes was released in October 2015, Nicholson transferred the work to the stage with a tour featuring characters from the book.