Whatever it is, I'm sure only Barrera himself knows. He definitely had some anger in him from something though.
If he needs the sole instruction of his corner to make moves for him, then he was'nt a bright x's and o's fighter to begin with. MAB's corner had sound advice for him, they did'nt want him to get into toe to toe trading with Pac. What MAB did in that fifth round was fine, get in, to some rough housing, and get out. However, there is a price to pay when you get up close to lay hands on Pac. If you get up close, you're going to feel Pacquiao's hands, and thats what MAB was'nt willing to do. MAB had already been obliterated by Pac in fight one, thats what was on MAB's mind..... It was MAB's choice and not his corner to run circles around Pac throwing a jab that was falling a foot short of its target.
About Barrera's anger and to answer the thread starters question...... MAB seems like a nice enough fellow, but my opinion of him is that his anger traits stem from him growing up a spoiled little brat. Coming from a poor backround does'nt translate to anger. MAB's anger issues flow with issues outside of the ring. He punched Morales in the face at a press conference. Morales was out talking him, and thats what spoiled little brats do when they are getting beat at something. MAB went public and was angry that GBP did'nt buy him a decision against JMM. MAB went as far as to say and insinuate that GBP did'nt want to see him win.......as if they had fixed the fight in JMM's favor. With MAB's spoiled brat tactics, he threatened GBP with leaving and showed the ugly side of himself in ranting and raving he wanted the Pac rematch. GBP who had promised the winner of Marquez-MAB would get Pac, went ahead and gave the crying ranting MAB the Pac fight instead of Marquez. My opinion, but thats where I think MAB's anger issues stem from. When he's not getting his way, he gets angry and acts like the spoiled little brat that he is.
There was alot of high hopes on him being the next JCC. He showed he was very intelligent when he adapted the counterpunching style and became greater and more versatile. He always reminded me of a samurai or Mexican samurai for some reason.
Just as boggling as Pac's all smiles on his way to the ring then suddenly transform into this wrecking machine with the intent of cutting your head off.