One theory is that it’s colder inside the SummerSlam arenas. WrestleMania is typically held outside in warm environments. Cena thrives in this environment because your boy is so hot that he’ll never be caught in the next man’s sweater. He also enjoys laying people down for the 3-second tan.
The lights inside the arena make it impossible to tan (they are not bright enough or close enough to the person tanning) and also increase the need for Cena to borrow the next man’s sweater.
Those are pretty good.
Seriously, though, I think Lambert hits it here:
Other wrestlers look at facing John Cena at SummerSlam for the World title as the second biggest match they could possibly achieve…and enter said match accordingly. Cena just sees it as another match.
I think in the back of Cena’s mind, he knows he made the wrong decision in 2010 against the Nexus, where he alone buried seven newcomers before they ever got a chance. It’s one of the worst blights of Cena’s career, and the prime example people talk about when they discuss Cena being bad for WWE. Ever since that event, Cena has used Summerslam as a place to put an up-and-comer over (I understand that Brock Lesnar (2014) may not seem like an up-and-comer, but in many ways that match rehabilitated Brock after a year-long story with HHH. It was the debut of the character Lesnar has to this day: a man only interested in hitting a few suplexes and his finishing move, because that’s apparently enough). It might have been a coincidence a few years in a row, but it’s been six Summerslam’s in a row where a wrestler looking to prove themselves to the WWE audience goes up against Big-Match-John. It’s also been six in a row where Cena feels the need to do what’s right for the company.
Having said that, I hope he squashes Baron Corbin in 30 seconds. I hate that guy.