Ahh, rollin'. It's what what we love to do. For many of us (me included), it's a huge part of what makes BJJ so awesome. When you make time to simply roll for round after round of with your teammates or other grapplers, your skills improve more rapidly. Sure, drilling is important and it's sort of the cornerstone of your BJJ practice. But, rolling, or sparring or free training (as we call it), is where you put it all into practice.
And, winning or losing, in the world of rolling, is irrelevant. Although it's competitive, rolling is not competition. Rolling is about being creative and advancing the very game you are creating. It's even meditative - when you roll properly, your conscious mind take a break and Jiu Jitsu takes over. All of life's worries leave you and you focus solely on the unconscious grappling craft.
Now that we've gotten you all metaphysical and zen, have a conscious look at the legend, Xande Ribiero rolling with 2012 World champ and Copa Podio champ, Leandro Lo.