In dancing terms, I see everyone as my "rival": when I see something in their dancing (not necessarily the entire thing, just a little aspect such as the way they position their arms, footwork etc.), I try to do it better in my own dancing. It doesn't matter whether the "rival" is a friend of mine or not, the only advantage I have over friends who are "rivals" is, that I can ask how they do "that and that move"

"Carpe diem, quam minimum credula postero." - Horace