The FA confirmed England's World Cup squad numbers during a training camp in Portugal last Thursday.
Wilshere was lying on a sun lounger at the time, drifting off after a long training session in which he was made to wear padded clothing to replicate the sweaty conditions he will encounter in Manaus.
Ordinarily the sleep denial would have peeved Wilshere after such an arduous session, but this was a welcome wake-up call because Beckham, England's most iconic number seven in recent times, also happens to be the Arsenal midfielder's idol.
"I was lying on a sunbed trying to go to sleep actually and a text came through saying I was number 7. That was it," Wilshere said with a broad smile.
"There has been Bryan Robson and David Beckham (who have worn seven) and now I have it. Beckham was my hero growing up as well so it is quite nice to get it."
Beckham, England's most-capped outfield player, features in almost every one of Wilshere's World Cup memories.
The Arsenal midfielder was only six at the time, but he remembers Beckham's dismissal in France '98 as well as his performances in 2002 and 2006.
Just like Beckham was in France, Wilshere heads into his first international tournament with few caps to his name.
But even though Wilshere has only 15 international appearances under his belt, he is by no means the baby of the group. Raheem Sterling, Ross Barkley, Daniel Sturridge and Luke Shaw are four of the 12 players in Roy Hodgson's squad who have fewer caps than the Gunners midfielder.
"Luke Shaw was born in '95. Oh my god," Wilshere said with a shocked expression on his face.
"I'm not the baby any more. Ross is '93. Raheem is '94...
"They have done well and they are here on merit."
The youthful look of Hodgson's squad has left Wilshere with an optimistic view on the tournament ahead.
"We are not going to say we are happy with the semis," he said.
"We are going there to win it."
Injury is the main reason why Wilshere is approaching 20 caps, rather than double that amount.
He missed Euro 2012 because of an ankle injury which kept him out for 16 months in total.
Alarm bells started ringing in March when he broke his foot against Denmark, but Wilshere is nearing full fitness after being eased back into action by Arsene Wenger.
Wenger was accused of failing to act in England's best interests three years ago when he advised against Wilshere's inclusion in the Under-21 squad for the European Championship after a season of toil at the Emirates.
But the Frenchman was deliberately cautious with Wilshere in his rehabilitation this time around as he did not want to ruin the 22-year-old's chances of going to Brazil.
"I came back training and I was panicking a bit about (making) the squad," Wilshere said.
"So I went to him (Wenger) and said: 'I think I am ready'.
"He said 'no you are not, you need to train if you are to have a good World Cup, you need a good fitness base and you need to make sure you are right in every aspect'. And that is what I am now."
Wilshere admits his injury problems have taken their toll on him psychologically.
"The more it happens the lower you get," he said.
Should any problems arise in Brazil, Wilshere will seek out Dr Steve Peters, the acclaimed psychiatrist who will accompany the team to Miami and South America.
He said: "It's good for top athletes because sometimes it can be tough mentally if you are not playing well or you feel things aren't going your way, it's good to talk to someone who can understands your brain."
Wilshere thinks his spell on the sidelines, and fatherhood, has made him a more mature man.
The way in which he handled criticism by Paul Scholes, who said the Arsenal man had not developed into the player he should be, suggests he is right.
Wilshere phoned Scholes to ask him for advice after a public dressing down and he may do so again during the tournament.
"He said to me: 'you've got my number now if you need anything ever just give me a call'," Wilshere added.
"It's nice to know that I can go to him any time and have a chat."
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