LAS VEGAS –  Luke Rockhold felt some first-time octagon jitters – he admits it. Despite his fair share of fights on the big stage, Rockhold said he definitely noticed a difference when he made his UFC debut in May against Vitor Belfort in Brazil. That fight resulted in a first-round knockout loss from a Belfort spinning kick to the head. “It was really bright,” Rockhold on Wednesday told MMAjunkie.com (www.mmajunkie.com) at a charity event in Las Vegas. “That’s the one thing that was a little different. (And) the mat was a little slippery – I’m not gonna lie