Gary was schooled at Graeme College in Grahamstown, matriculating in 1986, whereafter he did a post-matric at Kingswood College and then a BA LLB at Rhodes University where he graduated in 1991. After travelling overseas in 1992 he commenced articles in East London in 1993 at Marshall & Kaplan before joining Yazbeks Attorneys in 1995. He and Matthew Yazbek commenced practising as Stirk Yazbek Attorneys on 1 March 2014.
Gary was admitted as an attorney in 1995, as a conveyancer in 1996 and as a notary in 1997. He also has a tax diploma from RAU. He acts as a Small Claims Court Commissioner in East London.
He has run five Two Oceans marathons and presently enjoys mountainbiking, having completed numerous stage and other races. Other interests include red wine and bonsai.