Grant started golf in 1968 after playing many team sports. Golf has been in the Westthorp family for a long time with Gordon, Grants father being a Golf Professional since 1948. Grant completed the first year of his apprentiship under Gordon in 1976 at the Albany Golf Club.
Seeking further experience Grant travelled to England and gained employment under Geoffrey Cotton at Beckenham Place Park Golf Course in South London. Beckenham at the time was one of the busiest public courses in Europe. This provided a great foundation to launch a golf coaching career. In 1979 Grant was appointed Head Professional at Sidcup Golf Club in Kent.

Grant returned to Australia in 1981 to partner his father in Westthorp Golfing Sales of Albany. In 1984 Gordon retired and Grant expanded the business to incorporate retail and a wholesale golf company. In 1996 Grant sold out of the company to pursue a golf coaching career. In 2000 Grant suffered a near fatal health crisis which provided the motivation to start designing the Simpli Golf System. Since 2002 the Simpli Golf System has evolved from 16 golf lessons to 24 golf lessons. The Simpli Golf System is ready for worldwide release.