Teun is an artist known for a wide range of entrepreneurial adventures. He calls himself a ‘one-man conglomerate’. Castelein graduated from the Sandberg Instituut in 2006 with offering advertisement space on the facade of the institute. For the last five years he has been teaching Branding at the Willem de Kooning Academy in Rotterdam. He was nominated citizen on the year 2016 by the municipality of Amsterdam and is a member of the pop rock collective The Geert Wilders.