Prince Harry turns 40 on Sunday, September 15, and apart from millions of dollars of revenue from his memoir, Spare, and his good works with the Invictus Games, the Duke is said to “want more.” “I think in the back of Harry’s mind probably he’s thinking ‘I’ve got to get on with it, I’ve got to really go for it now,'” veteran royal author Ingrid Seward told The Sun. The Duke of Sussex completed a decade of service in the British Armed Forces in 2015. The idea for the Invictus Games came to him after he attended the Warrior Games in the U.S. in 2013, a competition for wounded, injured, or ill se…