Mok Koon has very humble beginnings. He is the fourth child in a family of six. His family was poor and education became a luxury as oppose to necessity. As a consequence, Mok Koon siblings had to drop out from school and worked to supplement the family's income as well as put the younger siblings through school. Through the sacrifices of Mok Koon older siblings and the education bursaries he received, Mok Koon eventually graduated from National University of Singapore with a Bachelor of Engineering (Honours) in Chemical Engineering.

After graduation, Mok Koon worked as an Engineer at Honeywell (S) Pte Ltd and ESSO Singapore Pte Ltd. He then joined Singapore Technologies Group in 1986 as an Engineer in the Engineering Project Division (now known as CSE Global Limited "CSE") managed under Chartered Electronic Industries before he was promoted to General Manager in 1992.

During the Asian financial crisis in 1997, Mok Koon was given the opportunity to exercise a management buy in of CSE. He took on the challenge and successfully bought out the company. He was appointed the Managing Director and Executive Director of CSE in 1997. Under Mok Koon‘s astute leadership, CSE propelled from a S$15 million local enterprise into a S$500 million international corporation with a Singapore public listing in 1999. In April 2015, he decided to retire from CSE Board of Directors. It is noteworthy to add during Mok Koon as Director of CSE Board, he had actively participated in CSE’s contribution towards community support which includes grant making and creating awareness of needs of the disadvantaged.

Mok Koon is keenly aware that much of his success is due to the support and mentorship he received from many selfless individuals he had met while building up his career. In this regard, he was filled with gratitude towards his benefactors and society which gave him opportunities in life. Further, the challenging environment that he endured in his younger years motivated him to reach out to the less fortunate who face similar predicaments as him. For these reasons, he felt compelled to give back to the society in the same fashion.

Through the TMK Charity Fund, Mok Koon hopes to formalize the process of giving in a structured approach. It is also his wish for good values to be passed on to his children and descendants and for them to continue the charitable legacy beyond his lifetime.