I'll answer this question in two ways, storyline wise and "backstage" wise. In storyline: Brock Lensar lost because he got overconfident and wrote Cena off after dominating him for the bulk of that match. I think it was pretty clear that Cena was outclassed in terms of sheer physicality, but he dug deep, didn't quit when it would have been very easy to and waited for his opening.
When Lesnar made a mistake, and it was a big one, Cena was ready and waiting to capitalize on it. He hammered him with that heavy chain loaded shot and delivered a thundering FU on those steel steps. Pretty tough to kick out of that combination, no matter who you are.
If that match had gone much longer, I think Brock would have won. He demonstrated a ridiculously high pain threshold and was picking Cena apart. He got cocky though, and because Cena had the heart to keep going and tough it out, it cost Lesnar.
Backstage wise: Cena HAD to win that match. He was fresh off losing "the biggest match of all time" to The Rock and had he lost to Lesnar, he would have looked like he couldn't hold a candle to the stars of yesteryear. Because of the way Lesnar fought, losing didn't hurt Brock at all, but winning sure as hell helped Cena.
There were questions, even on this forum, after Cena lost to The Rock that he didn't have what it takes to remain at the top of the WWE mountain. Defeating Lesnar, and going through hell to do it, stamped an exclamation point on the case that Cena is still The Man. It was a huge win for him credibility wise.
And looking long term, I think all these holy wars that Cena has been on are building towards an eventual feud with The Undertaker.
Because WWE need to protect their stupid-*** golden boy after losing to The Rock, so they let him win SuperCena style. FĂșck John Cena.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.