Arete is being excellent in everything you do, being the best. To get to the point of arete you must first go though struggles, arete isn't achieved easily and to get to that point you must fail and learn from your mistakes. Being the best at something may sound self-centered or conceded but people who are the best didn't become the best over night, they had to fail and go through something called "Agon" which means a struggle. People who are excellent at something have to go through agon to learn from there struggles and mistakes and learn how to make them better or fix them.
      Getting to the point of arete can become a time consuming and extraneous process. No matter what you are trying to accomplish, it will take time, hard work and dedication. Arete can consume you and your life, people who focus to much on being excellent can come off as being self centered and not even realize it. I have had many friends who are entirely focused on constantly being the best and at times they don't realize how wrapped up in there own world their in. The idea of arete can be dangerous, people can start to lose a sense or reality and become complete focused on one thing.
    Even though arete can become in a way an obsession, it is good to have a little of it in your life. It is important to have drive and motivation, with out arete it would be hard to want to be better. Wanting to be good, even great at what you do is a good thing, it keeps you motivated to keep growing and progressing in that area, arete can help you grow to your fullest potential over time.
    Arete and Agon are two very important things to have in your life, but I think that for each you have to have a balance, too much of one thing is never good. People who are highly motivated to be the best all the time have to learn to fail so they can grow and do better. It is good to have a balance because both arete and anon complement each other, you have to learn from your struggles (agon) to grown and eventually become the best (arete).