Why does Virat Kohli wear jersey number 18?

Virat Kohli, who completed 18 years in international cricket today, didn't choose jersey number 18, with the number initially being assigned to him during India Under-19 days. It later became personally significant as his father Prem Kohli died on December 18, 2006, while Kohli made senior India debut on August 18, 2008. Kohli described connection with the number as "cosmic".